Every new GPU generation ships with a free performance bump that most owners never turn on. It is not an overclock, it does not touch voltage, and it carries none of the stability risk that comes with pushing a card past its factory settings. It is a BIOS toggle called Resizable BAR, and on a modern RTX 50-series or RX 9000-series build it can be the difference between a card performing at spec and quietly leaving frames on the table. This guide walks through exactly how to enable Resizable BAR (ReBAR), what it needs from your CPU, motherboard, GPU, and Windows install, and how to confirm it is actually working once you flip the switch. We will also cover AMD’s version of the feature, Smart Access Memory, since the underlying steps overlap almost completely.
By the end you will have Resizable BAR enabled and verified through three separate tools, plus a troubleshooting list for the handful of ways this setting can go sideways on older boards. None of the steps below require opening the case. Everything happens in the BIOS/UEFI menu and inside Windows.
Timing matters here too. GPU prices have stayed elevated through September 2026, and most builders are holding onto the same card for longer than they used to, which makes a zero-cost setting change worth more than it was five years ago. Nvidia is still actively refining the feature as well. NVIDIA App 11.0.9 folded a manual per-game Resizable BAR control into the app’s regular update channel on September 3, 2026, retiring the old Early Access switch (full details in the advanced tips section below). If you already own a qualifying card and just have not gotten around to enabling the BIOS-level setting, that is exactly the gap this guide is meant to close.
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Quick Answer: Enable Resizable BAR in 4 Steps
Short on time? Here is the process compressed to its essentials, still accurate as of October 2026. The full 12-step walkthrough below breaks these four moves into a more granular, board-specific process, with exact BIOS menu paths for each major motherboard brand and a troubleshooting list.
- Update your motherboard BIOS/UEFI and your GPU driver (Nvidia, AMD, or Intel) to the current version.
- Boot into BIOS/UEFI setup, switch to Advanced Mode, and disable CSM/Legacy Mode so the board boots in full UEFI.
- Under PCI Subsystem Settings (naming varies by brand), enable Above 4G Decoding, then Resizable BAR Support (also labeled Re-Size BAR Support or Smart Access Memory), save with F10, and reboot.
- Confirm it took effect in GPU-Z (Advanced tab, Resizable BAR Enabled should read YES), NVIDIA Control Panel (Help → System Information, Resizable BAR should read Yes), or, on Radeon systems, AMD Software: Adrenalin Edition (Settings → Graphics, Smart Access Memory active).
What Resizable BAR Actually Does to Your GPU
To understand why this setting matters, it helps to know the limitation it removes. Under the original PCI Express specification, a graphics card exposes its video memory to the CPU through something called a Base Address Register, or BAR. For most of the PCIe era, that window was capped at 256MB, a holdover from 32-bit addressing conventions that made sense when GPUs shipped with a few hundred megabytes of VRAM total. Modern cards ship with 12GB, 16GB, even 32GB of VRAM on the RTX 5090. When the CPU needs to write textures, geometry, or shader data into that memory, it has to do it in small chunks through that narrow 256MB window, issuing far more read and write transactions than would be necessary if it could just address the whole frame buffer directly.
Resizable BAR, ratified as part of the PCI Express specification and pushed into mainstream consumer hardware starting in 2020, lets the BAR window scale up to match the GPU’s actual VRAM size. Instead of the CPU juggling small windows into GPU memory, it can address the entire frame buffer at once. In practice, that mostly helps in scenarios with a lot of small, frequent CPU-to-GPU memory writes, which is why open-world games with heavy texture streaming tend to show bigger gains than something like a competitive shooter that is already GPU-bound at high frame rates. It will not turn a mid-range card into a flagship. What it does is remove overhead that was never doing your GPU any favors in the first place, at no cost beyond a few minutes in the BIOS.
The feature’s official name in the PCI-SIG specification is the Resizable BAR Capability, an optional extension that PCIe device vendors could implement long before it reached consumer graphics cards. Enterprise hardware, including some data center GPUs, supported it years before Nvidia, AMD, and their motherboard partners built the necessary firmware and driver support into mainstream gaming hardware. That is worth knowing mainly because it explains why the rollout felt sudden in 2020 and 2021: the specification was not new, the consumer implementation was.
Resizable BAR vs Smart Access Memory: Same Feature, Different Name
If you have shopped for a Radeon card or an AMD motherboard, you have probably seen the term Smart Access Memory (SAM) instead of Resizable BAR. They are the same underlying PCIe feature. AMD introduced Smart Access Memory alongside the Ryzen 5000 series and Radeon RX 6000 series in late 2020 and marketed it as a benefit of pairing a Ryzen CPU with a Radeon GPU, according to AMD’s own Smart Access Memory product page. That framing led to some confusion, because the feature is not actually locked to same-brand combinations. Resizable BAR works with Intel or AMD CPUs and with Nvidia, AMD, or Intel GPUs, provided the motherboard, GPU firmware, and driver all support it.
So if your BIOS shows a setting called Smart Access Memory rather than Resizable BAR Support, do not treat it as a separate feature you need to research independently. Toggle it the same way you would toggle Resizable BAR, alongside Above 4G Decoding, and the rest of this guide applies without modification. Some AMD boards even show both labels in different BIOS revisions for the same physical setting.
Prerequisites: What You Need Before You Start
Resizable BAR is a chain of four dependencies. If any single link is missing, the option either will not appear in your BIOS or will not actually activate once you enable it. Before you touch any settings, confirm you have all four. A Gamerath walkthrough updated between October 4 and 16, 2026 boils the same chain down to three simultaneous requirements: a compatible GPU, a compatible CPU/motherboard BIOS, and a modern boot setup. It flags the same dependency emphasized in Step 6 below, too: CSM has to be disabled before Re-Size BAR will enable at all.
| Requirement | What You Need | How to Check |
|---|---|---|
| Motherboard BIOS/UEFI | A board built on UEFI (not legacy BIOS-only) with an Above 4G Decoding and Resizable BAR Support option, usually added via a firmware update on boards from 2019 onward | Check your motherboard maker’s support page for your model and current BIOS version |
| GPU | Nvidia RTX 30-series or newer, AMD RX 6000-series or newer, or an Intel Arc GPU | See the compatibility table below |
| GPU driver | Any current 2026 driver from Nvidia, AMD, or Intel already includes ReBAR support. Nvidia’s documented minimum is GeForce Game Ready Driver 465.89 WHQL or newer, a baseline it has shipped since March 30, 2021 | Open GeForce Experience/Nvidia App, AMD Software, or Intel Graphics Software and check for updates |
| Windows boot mode | Windows installed in UEFI mode on a GPT disk, not Legacy/MBR | Run the systeminfo command shown further down this guide |
Nvidia’s own guidance for desktop activation frames this from the GPU vendor’s side: a compatible CPU and chipset, a compatible motherboard, system firmware (SBIOS) updated if the specific board needs it, GPU firmware (VBIOS) that supports the feature, and a driver from the R465 branch or newer (the 465.89 WHQL release from March 30, 2021 noted in the table above was the first to qualify). As of October 2026 that baseline has not moved, so it remains a reliable checklist to run through before assuming a board or GPU simply is not supported.
Which GPUs Support Resizable BAR
Nvidia’s support for Resizable BAR begins with the GeForce RTX 3060, according to Nvidia’s official RTX 30-series announcement, and carries forward through every RTX 40-series and RTX 50-series card since they are newer hardware built on the same driver stack. Nvidia documentation dated October 15, 2026 frames the cutoff by architecture, saying GPUs from the Ampere generation onward support Resizable BAR when paired with a compatible motherboard. GTX-series cards, including the GTX 1660 and GTX 1080 Ti, do not support it. On the AMD side, HP’s OMEN support documentation names the Radeon RX 6600 and up as the starting point for Smart Access Memory, which extends to the RX 7000 and current RX 9000-series cards as later generations of the same architecture family. Intel’s entire Arc A-series lineup supports Resizable BAR, per the same HP guidance, and that support carries into the newer Arc B-series cards. Intel’s own support documentation covers the same Above 4G Decoding dependency on the platform side, since the CPU and chipset need to expose that addressing capability before any GPU, Intel’s own or otherwise, can use it. You can find Intel’s explanation of the requirement on its official support article on Resizable BAR.
| Current-Gen GPU | Rated Power (TDP/TBP) | ReBAR/SAM Support | Launch |
|---|---|---|---|
| Nvidia RTX 5090 | 575W | Yes | January 2025 |
| Nvidia RTX 5080 | 360W | Yes | January 2025 |
| Nvidia RTX 5070 Ti | 300W | Yes | 2025 |
| Nvidia RTX 5070 | 250W | Yes | 2025 |
| AMD RX 9070 XT | 304W | Yes | 2025 |
| AMD RX 9070 | 220W | Yes | 2025 |
If you are shopping rather than upgrading in place, every current-generation card worth buying in 2026 supports this feature by default, so it is one less thing to compare when you are weighing something like the RX 9070 against the RTX 5070.
Checking Your Current BIOS Mode
Resizable BAR will not activate on a system still running Legacy BIOS boot mode, even if every other requirement is met. Confirm your current mode before going any further by opening Command Prompt and running:
systeminfo | findstr /i "BIOS Mode"The output will read either BIOS Mode: UEFI or BIOS Mode: Legacy. If you see UEFI, skip ahead to the step-by-step section. If you see Legacy, you will need to convert your system disk to GPT before Resizable BAR can work, which is covered in the pitfalls section below.
How Much Performance Does Resizable BAR Actually Add?
HP’s OMEN support documentation puts the gain at up to 14% in select titles, while Bavit reports typical gaming gains of 2–8% on RTX 50, RX 9000, and Arc B GPUs in July 2026. Neither figure is universal. The size of the gain depends heavily on what you are running and at what settings.
Games with large open worlds, frequent texture streaming, and heavy draw-call counts tend to show the most noticeable improvement, since those are exactly the workloads that hammer the CPU-to-GPU memory path Resizable BAR is designed to widen. Competitive, CPU-bound titles running at already-high frame rates tend to show little to nothing, because the bottleneck in those games usually sits somewhere else entirely. Both Nvidia and AMD also maintain internal allow-lists inside their drivers. A small number of games actually run marginally worse with Resizable BAR forced on, which is why both vendors ship profiles that quietly disable it per-title rather than leaving it globally forced. For most titles you do not need to manage this yourself, since it happens automatically once the feature is enabled at the system level and a current driver is installed. For the handful of games missing a driver profile, Nvidia now offers a manual per-game override too, covered in the advanced tips below.
This is also why two people with the same GPU can report completely different experiences after enabling the feature. One is playing a sprawling open-world title that streams gigabytes of texture data every few minutes, the other is playing a locked, competitive shooter that was never going to be memory-bandwidth-limited in the first place. Neither person is wrong about what they saw. They are just measuring different workloads against the same setting.
The practical takeaway is to treat Resizable BAR as a system-level setting you turn on once and leave alone, not a per-game dial you fiddle with. Enable it at the BIOS level, keep your driver current, and let the driver’s own compatibility profiles handle the rest.
How to Enable Resizable BAR: Step-by-Step
These 12 steps cover the full process from checking your starting point to confirming the feature is live. Expect the whole process to take about 25 minutes, most of which is BIOS and driver updates rather than the actual toggle.
Step 1: Check Whether Resizable BAR Is Already Active
Some prebuilt systems and recent motherboards ship with Resizable BAR enabled out of the box. Before changing anything, confirm your starting point. Download GPU-Z, open it, click the Advanced tab, and select PCIe Resizable BAR from the dropdown. If GPU Hardware Support reads YES and BAR1 Size roughly matches your card’s total VRAM, it is already on and you can skip to the verification steps later in this guide. If it reads NO or the BAR1 size is stuck at 256MB, continue with the steps below.
Step 2: Confirm Your Hardware Qualifies
Cross-reference your GPU against the compatibility table earlier in this guide. If you are running a GTX-series Nvidia card or an AMD card older than the RX 6000 series, Resizable BAR is not available to you regardless of what you do in the BIOS, and you can stop here.
Step 3: Update Your GPU Driver
Install the latest driver from Nvidia, AMD, or Intel directly, rather than relying on whatever shipped with Windows Update. As of October 2026, every current driver already includes Resizable BAR support, but an outdated one may not. Nvidia sets a specific floor for activation: GeForce Game Ready Driver 465.89 WHQL or newer, a driver Nvidia first shipped on March 30, 2021. Anything you install today clears that bar automatically, but it is why a card that has not seen a driver update since an old Windows install can still fail to show the option. You can confirm your installed driver version from PowerShell:
Get-CimInstance Win32_VideoController | Select-Object Name, DriverVersion, DriverDateIf you are troubleshooting a driver that seems to be misbehaving after a recent GPU swap, a clean reinstall through Display Driver Uninstaller before installing the latest version removes any leftover configuration that could interfere.
Step 4: Update Your Motherboard BIOS/UEFI
This is the step people skip and then wonder why the option is missing. Boards from around 2019 onward generally added Resizable BAR support through a firmware update rather than shipping with it from day one. Download the current BIOS version (Nvidia and some board vendors label this an SBIOS update) from your motherboard manufacturer’s support page for your exact model and flash it using their update utility. If you have never updated your BIOS before, our full BIOS update walkthrough covers the process safely from start to finish, including what to do if the update interrupts partway through.
Step 5: Boot Into BIOS/UEFI Setup
Restart your PC and press the key your board uses to enter setup during boot, commonly Delete or F2. From the main screen, switch to Advanced Mode if your board opens into a simplified EZ Mode by default, since the options you need are typically hidden from the basic view.
Step 6: Switch the Boot Mode From CSM to Full UEFI
Find the Compatibility Support Module setting, usually under a Boot menu, and set it to Disabled. CSM exists to let UEFI motherboards boot older, Legacy-mode operating systems, and Resizable BAR cannot function while it is active. Intel’s own support documentation states this exact dependency: UEFI boot mode must be enabled and CSM (or Legacy Mode) must be disabled before Resizable BAR can activate, regardless of whether the installed GPU is Intel, Nvidia, or AMD. If your Windows install is currently running in Legacy/MBR mode rather than UEFI/GPT, do not disable CSM yet, since doing so can leave your system unable to find its boot drive. Handle the disk conversion first, covered in the pitfalls section below.
Step 7: Enable Above 4G Decoding
Navigate to your board’s PCI subsystem or chipset settings and set Above 4G Decoding (sometimes labeled Above 4G Memory) to Enabled. This setting allows PCIe devices to be mapped into memory addresses above the 4GB boundary and is a hard requirement for Resizable BAR, not an optional companion setting. The table below shows where to find it on the four major motherboard brands.
| Motherboard Brand | Typical BIOS Path | Settings to Enable |
|---|---|---|
| ASUS | Advanced Mode → Advanced → PCI Subsystem Settings | Above 4G Decoding, Resizable BAR Support |
| MSI | Advanced Mode → Settings → Advanced → PCI Subsystem Settings | Above 4G Memory/Decoding, Re-Size BAR Support |
| Gigabyte | Advanced Mode → Settings → IO Ports (or directly under Settings) | Above 4G Decoding, Re-Size BAR Support |
| ASRock | Advanced → Chipset Configuration (or PCI Configuration) | Above 4G Decoding, Re-Size BAR Support |
| Any other AMI/Insyde UEFI board | Check under Chipset, PCIe, or IO Ports submenus | Same two settings, naming may vary slightly by firmware version |
Exact wording and submenu depth shift between BIOS versions and board generations, even within the same brand. If you do not see it immediately under the path listed above, check nearby submenus before assuming your board does not support it. Both ASUS’s official Resize BAR FAQ and ASRock’s support FAQ walk through their respective menu layouts in more detail if your board’s screens do not match the summary above exactly. ASUS’s FAQ also lists a shortcut that works on many current boards: press Delete at boot to enter BIOS, click the Resize BAR icon right on the EZ Mode screen, set it to On, then press F10 and OK to save, without ever opening Advanced Mode.
Step 8: Enable Resizable BAR Support
Directly below or near the Above 4G Decoding option, find Resizable BAR Support (labeled Re-Size BAR Support on some boards, or Smart Access Memory on AMD-focused boards) and set it to Enabled. Some boards only offer Auto rather than a hard Enabled setting. Auto is fine, it will activate automatically once Above 4G Decoding is on and your hardware qualifies. ASUS Support’s own guidance, cited in an October 12, 2026 TechFuelHQ walkthrough, matches that advice exactly: Launch CSM set to Disabled, Above 4G Decoding set to Enabled, and Re-Size BAR Support set to either Enabled or Auto.
Step 9: Save Changes and Reboot
Press F10 (or your board’s designated save key, shown at the bottom of the screen) to save and exit. Confirm the prompt. Your system will restart on its own. The first boot after enabling Resizable BAR sometimes takes a little longer than usual while the system remaps memory addresses. That is expected and not a sign of a problem.
Step 10: Confirm Windows Booted Successfully in UEFI/GPT Mode
Once you are back at the desktop, rerun the systeminfo command from the prerequisites section to confirm BIOS Mode still reads UEFI. You can also confirm your disk’s partition style directly from PowerShell:
Get-Disk | Select-Object Number, FriendlyName, PartitionStyleYour system disk should show GPT. If it shows MBR, Resizable BAR will not activate even though the BIOS setting is enabled, and you will need to address the partition style before continuing.
Step 11: Verify Resizable BAR Is Actually Active
Do not assume the BIOS toggle alone means it is working. Confirm it through at least one of the following, ideally two for peace of mind. A review of the BIOS procedure published October 17, 2026 reaffirms the same order of operations covered in Steps 7 and 8 above (Above 4G Decoding enabled first, with Resizable BAR Support as the dependent toggle on top of it) and points to GPU-Z as the tool of record for confirming an active status once both are set.
- GPU-Z: Advanced tab → PCIe Resizable BAR dropdown. GPU Hardware Support and Resizable BAR Enabled should both read YES.
- Nvidia Control Panel: Help → System Information. Look for Resizable BAR in the details list, it should read Yes.
- AMD Software: Adrenalin Edition: Settings → Graphics. The Smart Access Memory toggle should show as active.
- Intel Driver & Support Assistant (Intel DSA): As of October 2026, Intel’s support documentation points to Intel DSA to confirm Resizable BAR on Intel platforms and Arc GPUs once Above 4G Decoding is enabled in BIOS/UEFI, rather than trusting the BIOS screen alone.
- Windows Device Manager: Open Display adapters, right-click your GPU, choose Properties, then check the Resources tab. As PC Games Hardware detailed in a September 16, 2026 report, this tab will show a much larger memory range than the old 256MB window once ReBAR is active, a quick vendor-agnostic check when you would rather skip GPU-Z or a control panel app.
Step 12: Benchmark Before and After to Confirm Real-World Gains
Run a repeatable benchmark, either a built-in game benchmark or a synthetic test, before and after enabling Resizable BAR. HP’s July 2026 guide recommends exactly two runs, one before and one after, to see what it actually did on your specific hardware and title mix. Since gains vary by game as covered above, this is the only way to know your real numbers rather than relying on someone else’s average.
Enabling Smart Access Memory on AMD Ryzen + Radeon
The BIOS-level steps above apply whether you are running Nvidia, AMD, or Intel hardware, since Above 4G Decoding and Resizable BAR Support live at the motherboard firmware level regardless of GPU brand. The one AMD-specific wrinkle worth knowing is that AMD’s own marketing history around Smart Access Memory can make people think it needs some kind of special same-brand pairing beyond the standard BIOS toggle. It does not. A Ryzen CPU paired with a Radeon GPU on a board with the setting enabled gets exactly the same feature that an Intel and Nvidia pairing gets elsewhere, just under AMD’s branding.
After enabling the setting in BIOS, verify it inside AMD Software: Adrenalin Edition rather than assuming it carried over automatically. Open the app, go to Settings, then Graphics, and confirm the Smart Access Memory toggle is active. If it is grayed out or missing, your GPU driver likely needs updating before the software can detect the feature your BIOS just enabled.
5 Common Pitfalls When Enabling Resizable BAR
Most Resizable BAR problems trace back to one of these five mistakes. Reading through them before you start will save you a round trip back into the BIOS.
- Disabling CSM before converting an MBR disk to GPT. If your Windows install is still on a Legacy/MBR disk and you disable CSM anyway, the system will not find a bootable drive. Confirm your partition style with the PowerShell command from Step 10 before touching CSM.
- Enabling Resizable BAR Support without Above 4G Decoding. These are two separate toggles and both are required. Enabling only one will leave the feature inactive even though a setting is technically flipped on.
- Skipping the BIOS update. An out-of-date board firmware is the single most common reason the Resizable BAR option does not appear in the menu at all, especially on boards purchased new in 2019 to 2021 before the feature was standard.
- Assuming an older GPU will work after a driver update. No driver update adds Resizable BAR support to hardware that does not support it at the silicon level, meaning GTX-series and pre-RX-6000 AMD cards. If your GPU is not in the compatibility table, no BIOS setting will change that.
- Not verifying activation and assuming the BIOS toggle was enough. A small number of setups show the setting as Enabled in BIOS but never actually engage it, usually because of a missed dependency elsewhere in this list. Always confirm through GPU-Z or your vendor’s software, not just the BIOS screen.
How Resizable BAR Interacts With Other PCIe Devices
Above 4G Decoding does not just affect your GPU. It changes how much memory-mapped I/O address space is available above the 4GB boundary for every PCIe device in your system, not only the graphics card. On most modern builds this is a non-issue, since motherboards ship with plenty of address space to spare. On older or more heavily populated systems, typically ones running several add-in cards at once, such as a capture card, an extra NVMe controller, a sound card, and a discrete GPU all in the same build, enabling Above 4G Decoding can occasionally surface a resource conflict that did not exist before, usually showing up as a device losing its driver or dropping to a degraded mode after the reboot.
If you run a build with several add-in cards and want to check for conflicts after enabling Resizable BAR, list your PCIe-attached devices and their current status from PowerShell:
Get-PnpDevice -Class Display,Net,SCSIAdapter | Select-Object FriendlyName, StatusAnything showing a Status other than OK is worth investigating in Device Manager. In most cases the fix is a BIOS update, since newer firmware revisions typically allocate address space more efficiently across multiple devices than early implementations did when the feature was still new.
Troubleshooting: Resizable BAR Problems and Fixes
If you have gone through every step above and something still is not right, work through this list in order.
- Resizable BAR Support option is missing entirely. Update your motherboard BIOS to the latest available version. If it is still missing after that, your board’s chipset may predate ReBAR support and no firmware update will add it.
- System will not boot after disabling CSM. Your Windows install is almost certainly on an MBR disk. Re-enable CSM to get back into Windows, then convert the disk to GPT using Microsoft’s MBR2GPT tool before trying again, or do a clean UEFI installation if you have a recent backup.
- Black screen after saving BIOS changes. Clear CMOS using your board’s reset button or jumper, which reverts to default settings, then reapply the changes one at a time, rebooting between each to isolate which setting caused the issue.
- GPU-Z still shows GPU Hardware Support as NO. This typically means your card genuinely does not support Resizable BAR at the hardware level. Double-check your exact model against the compatibility table, since some product lines include both supported and unsupported SKUs under similar names.
- Resizable BAR is enabled but shows no performance difference. This is expected in CPU-bound or competitive titles. Test in a GPU-heavy, texture-streaming title at a higher resolution before concluding the feature is not working.
- Setting reverts to Disabled after a BIOS update or CMOS reset. Both operations restore default settings. Simply reapply Above 4G Decoding and Resizable BAR Support after any future BIOS flash.
- Frame rate is slightly lower in one specific game after enabling ReBAR. A small number of titles run marginally worse with the feature active, which is why Nvidia and AMD drivers include per-game profiles that disable it automatically. Confirm you are on the latest driver, since older drivers may not include the correct profile for a newer game.
- Dual-boot system with Linux stopped booting into the other OS. Disabling CSM affects the entire boot chain, not just Windows. Confirm your Linux installation is also configured for UEFI boot before disabling CSM, or you may need to regenerate its boot entries afterward.
How to Disable Resizable BAR If Something Goes Wrong
Resizable BAR is fully reversible, which makes it a safe setting to experiment with. If you run into instability that you cannot resolve through the troubleshooting list above, or you simply want to confirm the feature is responsible for a problem you are seeing, reverting takes the same path as enabling it.
Boot back into BIOS/UEFI setup, navigate to the same PCI Subsystem Settings or Chipset Configuration menu, and set Resizable BAR Support back to Disabled. You can leave Above 4G Decoding and CSM as they are, since disabling just the ReBAR toggle is enough to fully deactivate the feature without touching your boot configuration. Save, exit, and reboot. Re-run the GPU-Z check from Step 11 to confirm it shows NO again before troubleshooting further.
Resizable BAR on Laptops vs Desktop PCs
Everything above applies most directly to desktop motherboards, where BIOS access is unrestricted and every setting is exposed. Laptops complicate the picture in two ways. First, many laptop manufacturers lock down their BIOS menus and do not expose Above 4G Decoding or Resizable BAR Support as user-adjustable options at all, even on machines with GPUs that technically support the feature. Whether it is available comes down entirely to what the manufacturer chose to expose, not anything you can unlock yourself without a modified firmware.
Second, laptops with hybrid graphics, where an integrated GPU and a discrete GPU share duty depending on the workload, add another layer of complexity. Resizable BAR generally needs the discrete GPU to be the primary display output, or at minimum needs Nvidia Optimus or AMD’s equivalent switching layer to correctly route the feature through to the discrete chip. If your laptop exposes the setting in its BIOS or through a vendor utility like an OEM control center app, enable it the same way as steps 7 through 9 above. If it is not exposed anywhere, your specific laptop model does not support user control over this feature, regardless of what GPU is inside it.
Resizable BAR on Prebuilt Desktops (HP, Dell, Lenovo, and Others)
Everything in the 12 steps above assumes a self-built PC with full BIOS access, but a large share of Resizable BAR searches come from people running a prebuilt desktop from HP, Dell, Lenovo, or a similar OEM, where the BIOS is often trimmed down to only the settings the manufacturer expects an average buyer to touch. The underlying PCIe feature and its Above 4G Decoding dependency are identical either way. The practical hurdle is simply whether the manufacturer chose to expose those two toggles in that simplified menu.
The boot key to reach BIOS/UEFI setup, and the general likelihood of finding Resizable BAR exposed at all, varies by brand. Treat the table below as a starting point rather than a guarantee, since OEMs frequently change BIOS layouts across model years and even across SKUs within the same model line.
| Prebuilt Brand | Common BIOS Entry Key | Above 4G Decoding / ReBAR Typically Exposed? |
|---|---|---|
| HP | Esc at boot, then F10 | Varies by model; check HP’s support page for your exact model number |
| Dell | F2 at boot | Varies by model; XPS and Alienware desktops expose it more often than budget Inspiron or OptiPlex units |
| Lenovo | F1 or F2 (Novo button on some models) | Varies by model; Legion desktops expose it more often than office-oriented ThinkCentre units |
| Acer, ASUS, and MSI prebuilts | Delete or F2 at boot | Gaming-branded lines generally expose more BIOS options than budget or office lines |
If your exact model does not show Above 4G Decoding or Resizable BAR Support anywhere in its BIOS menus, the setting has almost certainly been hidden rather than left out of the firmware entirely, since most current-generation prebuilts share the same motherboard chipsets found in DIY builds. Search your model number plus “BIOS” or “Resizable BAR” on the manufacturer’s own support site before concluding the option genuinely is not there, and check for a newer BIOS version while you are there. A firmware update occasionally exposes a previously hidden option on a prebuilt the same way it does on a standalone motherboard.
Advanced Tips: Getting the Most Out of Resizable BAR
Once Resizable BAR is confirmed active, a few additional habits keep it working correctly and help you understand what it is actually contributing to your system.
Re-verify after every driver update. Nvidia, AMD, and Intel periodically update their internal per-game ReBAR profiles alongside regular driver releases. A fresh install occasionally resets related settings inside the vendor control panel even though the BIOS-level toggle is untouched, so a quick check in GPU-Z after major driver updates is worth the ten seconds it takes.
NVIDIA App 11.0.9: Per-Game Resizable BAR Control
Use the NVIDIA App’s per-game toggle for edge cases. Guru3D lists September 3, 2026 as the release date for NVIDIA App 11.0.9, which folded manual per-game Resizable BAR control into the app’s regular update channel, no Early Access switch required. Open the app and follow Graphics → Program Settings, select the specific game from the list, then open Driver Settings → Resizable BAR, where Auto, Enabled, and Disabled options are available with Auto set as the default. That puts a per-game override inside the app itself instead of leaving Resizable BAR as an all-or-nothing BIOS setting, though it does not replace anything in the step-by-step section above and will not add Resizable BAR support to hardware that lacks it. It just gives you a manual switch for the rare game that is not already handled by Nvidia’s built-in compatibility profiles.
Export your system report for troubleshooting or support tickets. If you ever need to share your configuration with a motherboard vendor’s support team or a forum thread, export a full diagnostic report rather than typing out specs by hand:
dxdiag /t C:dxdiag_report.txtThis generates a full text report covering your GPU, driver version, and system configuration, which is far more useful to a support technician than a screenshot.
Pair it with other free BIOS-level gains. Resizable BAR is one of a handful of no-cost settings worth checking in the same BIOS session. If you have not already enabled your memory’s rated speed, our guide to enabling XMP or EXPO for RAM covers a similar one-time BIOS toggle that is easy to bundle into the same reboot.
Do not confuse this with GPU overclocking or undervolting. Resizable BAR is a memory-addressing feature, not a clock speed or voltage adjustment. If you are looking to push additional performance out of your card through actual overclocking, that is a separate process covered in our GPU overclocking guide, and it carries different risks than anything covered here.
A Complete Walkthrough: Before and After on a 2026 Build
To tie the whole process together, here is what the full sequence looks like end to end on a typical current-generation build, for example a Ryzen-based system paired with an RTX 5070 Ti on an ASUS AM5 motherboard.
Before making any changes, GPU-Z’s PCIe Resizable BAR panel shows GPU Hardware Support as YES, since the RTX 5070 Ti qualifies, but Resizable BAR Enabled reads NO and BAR1 Size sits at 256MB. Running systeminfo | findstr /i "BIOS Mode" confirms the system is already on UEFI, and Get-Disk confirms the system disk is GPT, so no partition conversion is needed, a common state for any PC built within the last several years.
After updating the motherboard BIOS to the current version, entering Advanced Mode, and navigating to Advanced → PCI Subsystem Settings, both Above 4G Decoding and Resizable BAR Support appear as options, both set to Disabled by default. Setting both to Enabled, saving with F10, and rebooting takes under two minutes total. Back at the desktop, GPU-Z now shows Resizable BAR Enabled as YES and BAR1 Size matching the RTX 5070 Ti’s full 16GB frame buffer instead of the old 256MB window. Nvidia Control Panel’s System Information panel confirms the same result under its Resizable BAR field.
From there, the actual frame rate impact depends entirely on what you play, consistent with HP’s documented range of up to 14% in select titles cited earlier in this guide. A texture-heavy open-world game is the best test case if you want to see the feature doing real work, run your usual benchmark run or a repeatable in-game bench before drawing conclusions specific to your own library.
The entire process, from the first BIOS update download to the final GPU-Z confirmation, took under 20 minutes on this build, with most of that time spent waiting for the BIOS flashing utility to finish rather than navigating menus. That lines up with the 25-minute estimate at the top of this guide, and it is a reasonable planning number whether you are on an ASUS, MSI, Gigabyte, or ASRock board, since the individual steps are short even when the exact menu wording differs. Builders coming from an older platform with a Legacy/MBR install should budget extra time for the disk conversion covered in the pitfalls section, which is the one step here that is not a quick toggle.
Frequently Asked Questions
Is Resizable BAR safe to enable?
Yes. Unlike overclocking or undervolting, Resizable BAR does not change clock speeds, voltages, or power limits. It changes how the CPU addresses GPU memory. The worst-case outcome from enabling it incorrectly is a failed boot from a CSM/MBR mismatch, which is fully recoverable by re-enabling CSM or clearing CMOS.
Does Resizable BAR increase FPS in every game?
No. Gains concentrate in GPU-bound, texture-streaming-heavy titles, and HP documents gains of up to 14% in select titles. CPU-bound or competitive titles running at already-high frame rates typically show little to no difference, and a small number of titles are excluded from the feature entirely through vendor driver profiles.
Do I need to enable Resizable BAR and Above 4G Decoding separately, or does one turn on the other?
They are separate settings and both must be manually enabled. Above 4G Decoding is a prerequisite that allows the memory addressing Resizable BAR needs, but enabling it alone does not activate Resizable BAR.
Can I use Resizable BAR with an older CPU?
Resizable BAR is primarily a motherboard firmware and GPU feature rather than a CPU-generation requirement, so most CPUs that support UEFI boot mode work fine as long as the motherboard, GPU, and OS boot mode all meet the requirements covered in this guide.
Why don’t I see a Resizable BAR option in my BIOS at all?
The most common cause is an outdated motherboard BIOS. Update to the latest firmware version from your board manufacturer’s support page first. If the option is still missing after that, your board’s chipset generation may not support the feature at all.
Does Resizable BAR work with laptop hybrid graphics setups?
It can, but only if the laptop manufacturer exposes the setting and the system correctly routes it through Optimus or AMD’s equivalent GPU-switching layer. Many laptops do not expose BIOS-level control over this setting to the user at all, in which case there is nothing to enable manually.
Will enabling Resizable BAR void my warranty or damage my hardware?
No. It is a standard, vendor-supported feature built into current GPU drivers and motherboard firmware, not a modification outside normal operating parameters. Enabling it carries no more warranty risk than updating your BIOS or GPU driver.
How do I know if Resizable BAR is actually helping, versus just enabled?
Confirm it is active through GPU-Z, Nvidia Control Panel, or AMD Software as covered in Step 11, then run a repeatable benchmark before and after in a GPU-bound title. Being enabled and delivering a measurable difference in your specific game library are two different things worth checking separately.
Do I still need the BIOS steps if I have the new NVIDIA App per-game toggle?
Yes. The per-game Resizable BAR control Nvidia added in NVIDIA App 11.0.9 as of September 3, 2026 only adjusts behavior for individual games on a system where Resizable BAR is already enabled at the BIOS level. It does not replace Steps 1 through 12 above, and it cannot add Resizable BAR support to hardware or a board that does not meet the CSM, Above 4G Decoding, and firmware requirements covered earlier in this guide.
Do I need NVIDIA App 11.0.9 specifically, or will an older version show the same toggle?
Yes, you need 11.0.9 or newer. That release is what moved the per-game Resizable BAR control out of Early Access and into the app’s regular update channel on September 3, 2026, so any build older than 11.0.9 will not show the Driver Settings → Resizable BAR entry under Graphics → Program Settings. Update through the NVIDIA App’s own updater or grab the current installer from Nvidia directly. This only changes the per-game override, not core Resizable BAR functionality, which still depends on the BIOS steps above rather than any particular app version.
Does Resizable BAR require PCIe 4.0 or PCIe 5.0?
No. Resizable BAR is part of the base PCI Express specification rather than a feature tied to one PCIe generation, so it works over PCIe 3.0, 4.0, and 5.0 links alike. What determines support is whether your CPU, motherboard firmware, and GPU implement it, not which PCIe generation the slot runs at. A GPU seated in a PCIe 3.0 x16 slot on an older platform can still use Resizable BAR as long as the other requirements in this guide are met.
Does Resizable BAR work on Linux?
Yes. Resizable BAR lives in BIOS/UEFI and PCIe firmware rather than inside any specific operating system, so the same Above 4G Decoding and Resizable BAR Support toggles apply no matter which OS you boot afterward. Current Nvidia, AMD, and Intel Linux drivers pick it up automatically once it is enabled in firmware, and there is no separate Linux-only BIOS setting to look for.
Can I enable Resizable BAR on a prebuilt desktop from HP, Dell, or Lenovo?
Sometimes. The BIOS on prebuilt desktops is often locked down to fewer options than a standalone motherboard, so whether Above 4G Decoding and Resizable BAR Support appear at all depends on your specific model rather than the brand as a whole. Gaming-oriented lines like HP Omen, Dell Alienware, and Lenovo Legion are more likely to expose the setting than office-focused desktops. Check your model’s BIOS menus directly, using the brand’s common entry key from the prebuilt section above, and consult the manufacturer’s support page for your exact model number if you do not see it.
Why does my prebuilt PC not show an Above 4G Decoding or Resizable BAR option at all?
Most likely the manufacturer chose not to expose it in a simplified BIOS menu, not that the hardware lacks support. Confirm your GPU and general chipset generation qualify using the compatibility table earlier in this guide, then check the manufacturer’s support page for a newer BIOS version, since some OEMs add the option in a later firmware update the same way standalone motherboard vendors do.
