Microsoft and Sophos both rebuilt their detection-and-response stacks this fall, and the timing is not a coincidence. Microsoft pushed the Integrated Security Operations Center (ISOC) into preview on September 23, 2026, folding SIEM, XDR, threat intelligence, and AI agents into the Defender portal. Eight days earlier, Sophos finished rolling out Sophos XDR Powered by Secureworks alongside a brand-new Sophos Next-Gen SIEM and an expanded MDR service. Two of the industry’s biggest endpoint vendors landed major platform rewrites inside the same six-week window, and security teams evaluating either one in October 2026 are asking the same question: which platform actually catches more and costs less to run.
This comparison pulls apart Microsoft Defender XDR and Sophos XDR on architecture, pricing mechanics, independent benchmark data, and real deployment patterns. It is not a marketing recap. It is the numbers: a $2.40-per-GB ingestion meter, a 90-day retention clock that starts ticking November 15, 2026, a 4.6 operational-maturity score, and a market-share gap that still runs nearly six to one in Microsoft’s favor. By the end, you will know exactly which platform fits which kind of security team, and what it costs to switch between them.
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What Is Microsoft Defender XDR in 2026?
Microsoft Defender XDR is the unified detection-and-response layer that sits across Microsoft 365, Entra ID, endpoints, cloud workloads, and email. It correlates signals from Defender for Endpoint, Defender for Office 365, Defender for Identity, and Defender for Cloud Apps into a single incident graph instead of forcing analysts to pivot between four separate consoles. That correlation engine has existed since 2021, but the big change in 2026 is what Microsoft bolted on top of it.
The Integrated Security Operations Center (ISOC) entered preview in September 2026 and merges SIEM capability, XDR, threat intelligence, automation, and AI agents directly inside the Defender portal, according to Microsoft’s own Defender XDR changelog. Starting September 23, 2026, ISOC became available to eligible Microsoft 365 E5 and E7 customers without requiring them to stand up a separate Microsoft Sentinel workspace first. That is a meaningful shift: previously, getting SIEM-grade correlation meant provisioning and paying for Sentinel as a distinct product. Now it ships as a benefit layered onto the license tenants already hold.
Microsoft is positioning ISOC as a shared data and control plane, one that both human analysts and autonomous AI agents can query against. That framing matters because it signals where Microsoft expects the next wave of SOC work to happen, inside agent-driven triage rather than manual alert queues. BlueVoyant, a managed security provider, has already built an agentic MXDR365 operations layer specifically to sit on top of ISOC, which is a strong early signal that the ecosystem is treating ISOC as infrastructure rather than a feature.
What Is Sophos XDR Powered by Secureworks?
Sophos took a different path to the same destination. On August 31, 2026, Sophos announced that Sophos XDR Powered by Secureworks, a brand-new Sophos Next-Gen SIEM, and an expanded Sophos MDR service all reached general availability, according to the official Sophos partner announcement. This is the latest chapter of what Sophos calls its Fusion platform, the unified architecture that ties together EDR, XDR, MDR, and now SIEM under one roof following Sophos’s acquisition of Secureworks’ Taegis technology.
The September 2026 update expanded Fusion with three genuinely new products rather than incremental patches: Sophos Next-Gen SIEM, Sophos AI Defense, and Sophos CISO Advantage, according to Sophos’s community upgrade center. Next-Gen SIEM adds broader third-party integrations, deeper embedded threat intelligence, prebuilt automation playbooks, and a reworked analyst console. Sophos also folded in a new Email Monitoring System, stretching its detection surface past endpoint telemetry and into inbox-level signal, something that previously required a bolt-on from Sophos’s email security line.
Crucially, Sophos is not forcing every customer onto the new stack at once. The company confirmed the rollout to existing tenants is staged over several months rather than flipped as a single cutover, which matters if you are mid-renewal and trying to plan around which version of the platform you will actually be running by early 2027.
Microsoft Defender XDR vs Sophos XDR: Full Specs Comparison
The table below lines up both platforms across the dimensions that actually drive a purchase decision: architecture, ingestion economics, retention, platform coverage, and where each vendor stands in independent evaluations.
| Dimension | Microsoft Defender XDR (ISOC) | Sophos XDR (Fusion) |
|---|---|---|
| Core architecture | Unified Defender portal; SIEM, XDR, threat intel, automation, AI agents in one pane | Fusion platform combining EDR, XDR Powered by Secureworks, MDR, and new Next-Gen SIEM |
| SIEM integration | Native, built into ISOC as of September 23, 2026; no separate Sentinel workspace required for eligible tenants | Native, via new Sophos Next-Gen SIEM, GA since August 31, 2026 |
| Data retention | 90 days of Defender data retention beginning November 15, 2026 | Varies by MDR/XDR tier; no single published retention meter |
| Non-vendor data ingestion pricing | $2.40 per GB for non-Microsoft data, metering starts October 1, 2026 | Bundled into Next-Gen SIEM and MDR packages; no public per-GB meter disclosed |
| License prerequisite | Microsoft 365 E5 or E7 (eligible tenants) | Sophos Central tenancy with Intercept X and/or MDR subscription |
| AI/agent layer | Positioned as shared control plane for human analysts and autonomous AI agents | New Sophos AI Defense module, launched alongside Next-Gen SIEM |
| Email security correlation | Defender for Office 365 feeds directly into the XDR incident graph | New Sophos Email Monitoring System extends detection into inbox telemetry |
| Managed detection option | Available via Microsoft Defender Experts and third-party MXDR partners like BlueVoyant | Sophos MDR, expanded as part of the same August 2026 GA |
| CISO-level reporting | Built into existing Defender/Sentinel reporting workflows | New Sophos CISO Advantage module, launched September 2026 |
| Operational maturity score (independent assessment) | 4.6, highest documented score among assessed EDR offerings | Not separately scored in the same published assessment |
| Shipped-innovation score | 3.0, tied with CrowdStrike Falcon Insight XDR | Not separately scored in the same published assessment |
| 2024 worldwide endpoint security market share | 28.6%, according to IDC data cited by CRN | 5.0%, according to the same IDC dataset |
| Forrester Wave XDR rating (Q2 2024) | Highest possible rating in 15 of 22 evaluation criteria | Evaluated among 11 vendors across the same 22 criteria |
| Rollout cadence for existing customers | Phased preview-to-GA, tied to E5/E7 licensing eligibility | Staged rollout spanning several months after August 2026 GA |
Two things jump out immediately. First, Microsoft’s $2.40-per-GB ingestion fee is the only hard, published per-unit price either vendor has put on the table this year, which makes Defender XDR unusually easy to model against your actual log volume. Second, the market-share gap, 28.6% versus 5.0% per IDC’s 2024 figures, is not new; it reflects years of Microsoft bundling security into the Microsoft 365 suite that most enterprises already license. Sophos is competing on depth and flexibility rather than installed base, which shows up clearly in how each company is spending its 2026 roadmap.
Benchmark Data: How Independent Evaluators Score Each Platform
Marketing pages are not benchmarks. Here is what three independent sources actually measured between 2024 and October 2026.
| Evaluation source | Metric | Microsoft Defender XDR | Sophos XDR / Intercept X |
|---|---|---|---|
| Forrester Wave: XDR Platforms, Q2 2024 | Highest-rating count across 22 criteria | 15 of 22 criteria rated highest possible | Included among 11 vendors evaluated; not the top scorer |
| IDC Worldwide Corporate Endpoint Security, 2022 | Market share | 18.9%, ranked No. 1 | Not among the top-ranked vendors in that report |
| IDC Worldwide Modern Endpoint Security, 2024 | Market share | 28.6% | 5.0% |
| Atlas of Security EDR assessment, Sept-Oct 2026 | Operational maturity score | 4.6 (highest documented in the group) | Not separately published in this dataset |
| Atlas of Security EDR assessment, Sept-Oct 2026 | Shipped-innovation score | 3.0 (tied with CrowdStrike Falcon Insight XDR) | Not separately published in this dataset |
| CiteWorks Studio AI-search recommendation coverage, October 2026 | Share of AI-assistant security recommendations | Not the lead name in this specific dataset | Sophos Intercept X remained among the most visible competing names, behind CrowdStrike Falcon |
The pattern across every independent dataset is consistent: Microsoft wins on documented maturity and market share, while Sophos holds visibility as a credible alternative without topping any of the published rankings. One wrinkle worth watching is Arctic Wolf, a managed-detection vendor that is not part of this head-to-head but whose AI-search recommendation coverage jumped from 17.3% in July 2026 to 24.4% in October 2026, a 7.1-point swing in three months according to CiteWorks Studio’s tracking. That kind of movement shows the MDR market is still reshuffling fast, and neither Microsoft nor Sophos has it locked down.
The Broader XDR Market: Where CrowdStrike and Arctic Wolf Fit In
Neither Microsoft nor Sophos operates in a vacuum, and reading the benchmark numbers in isolation can be misleading. CrowdStrike Falcon led October 2026 AI-search recommendation coverage among cybersecurity tools, widening its gap over Sophos Intercept X in that specific dataset, according to CiteWorks Studio’s monthly tracking. That matters for this comparison because it shows Sophos is not just chasing Microsoft, it is also fending off a third major competitor that neither this article’s two subjects fully neutralize. CrowdStrike’s Falcon Insight XDR tied Microsoft Defender for Endpoint Plan 2 on the 3.0 shipped-innovation score in the Atlas of Security assessment, which tells you the innovation race at the top of the EDR market is closer than the operational-maturity numbers alone suggest.
Arctic Wolf is the other name worth watching, even though it is not a direct subject of this Microsoft-versus-Sophos comparison. Its AI-search recommendation coverage climbed from 17.3% in July 2026 to 24.4% in October 2026, a 7.1-point jump in three months. That is a managed-detection-and-response vendor gaining ground fast, and it is a reminder that both Microsoft and Sophos are competing for budget against pure-MDR players, not just against each other. An organization comparing Defender XDR and Sophos XDR in isolation risks missing a third option that is growing faster than either in a specific, measurable way. The practical takeaway for buyers: run your shortlist against at least one MDR-first vendor alongside these two platform-first options before signing anything, since the market is still moving.
Pricing Breakdown: ISOC’s Metered Model vs Sophos Fusion Bundles
Pricing is where the two platforms diverge most sharply in philosophy, and it is also where buyers get burned if they do not read the fine print. Neither Microsoft nor Sophos publishes a flat per-seat list price for XDR in the way a SaaS tool like Slack or Notion does; both are tiered behind license bundles and quote-based MDR contracts. What is publicly documented, though, tells a clear story about where the real cost risk sits.
| Cost driver | Microsoft Defender XDR / ISOC | Sophos XDR / Fusion |
|---|---|---|
| Base access | Included for eligible Microsoft 365 E5 and E7 tenants | Requires Sophos Central plus Intercept X and/or MDR subscription |
| SIEM add-on cost | No separate Sentinel workspace fee required for ISOC-eligible tenants as of September 23, 2026 | Sophos Next-Gen SIEM bundled into Fusion packages, GA since August 31, 2026 |
| Data retention window | 90 days of Defender data retention starting November 15, 2026 | Varies by subscribed tier; no single published retention figure |
| Non-native data ingestion | $2.40 per GB for non-Microsoft data, effective October 1, 2026 | No public per-GB meter; costs folded into Next-Gen SIEM and MDR tier pricing |
| Managed detection add-on | Microsoft Defender Experts and third-party MXDR partners, quote-based | Sophos MDR, expanded GA August 2026, quote-based |
| Cost predictability for log-heavy environments | High: a known per-GB rate lets teams model non-Microsoft log costs precisely | Lower transparency: bundled pricing makes it harder to isolate the SIEM cost line item |
The $2.40-per-GB figure deserves its own callout. Patriot Consulting, a Microsoft security partner, launched a free ISOC cost-evaluation service specifically because that meter can swing total cost of ownership significantly for organizations piping large volumes of third-party log data, firewall telemetry, cloud provider logs, SaaS audit trails, into Defender’s new SIEM layer, according to a September 30, 2026 announcement. A mid-sized enterprise ingesting even 2TB of non-Microsoft log data per month would see roughly $4,800 in ingestion fees alone, on top of whatever E5 or E7 licensing it already carries. Sophos avoids that exposure by bundling SIEM cost into its subscription tiers, but the tradeoff is less visibility into exactly what you are paying for the SIEM layer versus the EDR layer versus MDR.
Architecture Deep Dive: Shared Data Plane vs Fusion Stack
The deepest technical difference between these two platforms is not features, it is where correlation happens. Microsoft’s ISOC model treats the Defender portal as a shared data and control layer: every signal, whether from Defender for Endpoint, Entra ID, Defender for Cloud Apps, or an ingested third-party feed, lands in one normalized data plane that both human analysts and AI agents query against. That is a deliberate architectural bet that the next generation of SOC tooling will be agent-native, with autonomous triage running directly against the same signal store analysts use.
Sophos’s Fusion architecture takes a federated approach instead. XDR Powered by Secureworks, the new Next-Gen SIEM, MDR, AI Defense, CISO Advantage, and Email Monitoring System are built as distinct but interoperating modules rather than one monolithic data plane. That gives Sophos more flexibility to sell modules independently, a customer can run Intercept X and MDR without the SIEM, for example, but it also means cross-module correlation depends on how tightly Sophos has wired the integrations between each piece, something the company is actively still building out given the staged, multi-month rollout it confirmed for existing customers.
For security engineering teams writing detection logic, this difference shows up directly in how you query data. A typical Defender XDR hunting query against the unified ISOC data plane looks like this in Advanced Hunting’s KQL dialect:
// Simplified illustrative example of a cross-signal hunting query
// joining endpoint and identity telemetry inside the Defender XDR data plane
DeviceLogonEvents
| where Timestamp > ago(7d)
| where LogonType == "Network"
| join kind=inner (
IdentityLogonEvents
| where Timestamp > ago(7d)
| where ActionType == "LogonFailed"
) on AccountName
| summarize FailedAttempts = count() by AccountName, DeviceName
| where FailedAttempts > 10
| order by FailedAttempts descBecause Defender for Endpoint and Defender for Identity feed the same ISOC data plane, that join happens natively without an export-and-reimport step. In a federated Fusion-style architecture, the equivalent cross-module correlation typically depends on how the vendor has wired module-to-module data sharing, which is why Sophos’s staged rollout timeline for Next-Gen SIEM integrations is worth tracking closely if deep cross-signal hunting is a priority for your team.
The AI Agent Layer: ISOC’s Control Plane vs Sophos AI Defense
Both vendors shipped an AI-focused capability in this same release window, and the framing difference is worth calling out separately from the architecture discussion above. Microsoft’s ISOC is explicitly described as a shared foundation of signals, context, and controls for security teams and AI agents, meaning the data plane itself was designed from day one to be queried by autonomous software, not just human analysts clicking through a console. That is a structural decision: Microsoft is betting that the next generation of tier-1 triage work gets handled by agents operating directly against the same incident graph a human analyst would use, rather than against a separate, bolted-on automation layer.
Sophos AI Defense, launched as part of the same September 2026 Fusion expansion that brought Next-Gen SIEM and CISO Advantage, takes a more modular approach. It is positioned as a discrete capability inside the Fusion stack rather than a redesign of the underlying data plane itself. That is consistent with Sophos’s overall federated architecture: rather than rebuilding Sophos Central’s core data model around agent-native queries, Sophos is adding AI capability as a component that plugs into the existing EDR, XDR, and MDR modules. For a security team trying to decide which approach fits their SOC roadmap, the practical question is whether you want AI agents operating against a unified signal store from the ground up (Microsoft’s bet) or layered on top of a modular platform you can adopt piece by piece (Sophos’s bet). Neither approach has a multi-year track record yet, since both shipped within the same six-week window in September 2026, so teams evaluating this dimension should treat it as a roadmap decision rather than a benchmarked one.
Real-World Deployment Patterns: Where Each Platform Fits
Neither vendor has published granular named customer case studies with hard metrics for these specific 2026 releases yet, since both ISOC and Sophos Fusion’s expansion are only weeks old. What is clear from how each platform is architected and licensed is which deployment patterns line up naturally with each.
- A 6,000-seat Microsoft 365 E5 enterprise consolidating four security consoles into one: this is the exact scenario ISOC was built for, since the SIEM capability rides on the licensing tenants already carry without a separate Sentinel provisioning step.
- A multinational retailer running mixed Windows, macOS, and Linux point-of-sale infrastructure: Sophos’s cross-platform EDR heritage and Fusion’s modular MDR tiers fit environments where not every endpoint lives inside the Microsoft ecosystem.
- An MSP managing 40-plus SMB tenants: Sophos Central’s multi-tenant console and the newly expanded MDR service are built around managing many small customers from one pane, which is a different operating model than Defender’s enterprise-tenant-first design.
- A financial services firm with strict 90-day-plus audit retention requirements: Microsoft’s newly published 90-day Defender data retention window starting November 15, 2026 gives compliance teams a concrete figure to validate against regulatory retention mandates, something that needs direct confirmation against Sophos’s tier-dependent retention policy.
- A healthcare network piping firewall, VPN, and cloud audit logs into a central SIEM: this is exactly the use case where Microsoft’s $2.40-per-GB non-Microsoft ingestion fee needs careful volume modeling before committing, since high-volume log sources outside the Microsoft stack can add up fast.
- A lean 200-person SaaS company without a dedicated SOC: Sophos MDR Complete or Microsoft Defender Experts both offload 24/7 monitoring, but the decision usually comes down to which ecosystem the company’s existing endpoint and identity tooling already sits inside.
What Industry Research Says About XDR Platform Maturity
Independent research firms have been tracking this market for years, and their data provides useful context for how these 2026 platform updates land against a longer baseline.
According to Forrester’s Wave report on Extended Detection and Response platforms, “Microsoft Defender XDR received the highest possible rating in 15 of 22 evaluation criteria” in the Q2 2024 assessment. That same evaluation confirms that “the Forrester Wave evaluated 11 XDR vendors, including Microsoft and Sophos, across 22 criteria,” which means both platforms sat in the same formal evaluation even though Microsoft came out on top of the majority of scored dimensions.
On market share, IDC’s research is equally direct. A 2025 CRN report citing IDC data states that “Microsoft held 28.6% of the worldwide modern endpoint security market in 2024, compared with Sophos at 5.0%.” That gap traces back further, too: Microsoft’s own security blog cites IDC’s 2022 report showing “Microsoft held 18.9% of the worldwide corporate endpoint security market in 2022,” a figure that ranked Microsoft Defender for Endpoint number one in that category at the time. Taken together, these numbers show Microsoft has not just maintained its lead since 2022, it has nearly expanded it by a further ten points, while Sophos has held a stable but comparatively small slice of the overall endpoint security market.
Best Use Cases for Microsoft Defender XDR
Defender XDR makes the most sense for organizations already standardized on Microsoft 365 E5 or E7, where ISOC’s SIEM capability arrives as a licensing benefit rather than a net-new purchase. It is also the stronger fit for security teams that want to build around AI-agent-driven triage, since Microsoft has explicitly architected ISOC as a shared data plane for both analysts and autonomous agents. Teams prioritizing documented operational maturity, Defender for Endpoint Plan 2 scored 4.6 in the most recent Atlas of Security assessment, will also find the independent data stacks in Microsoft’s favor. Finally, organizations that need predictable per-GB cost modeling for SIEM ingestion benefit from the transparency of a published $2.40-per-GB rate, even if that rate itself requires careful volume planning, and teams already running the Microsoft Defender email security stack will find ISOC’s correlation layer extends that investment rather than replacing it.
Best Use Cases for Sophos XDR
Sophos XDR fits organizations running heterogeneous, non-Windows-heavy environments where a Microsoft-centric data plane does not naturally cover every endpoint. It is also the stronger choice for MSPs and lean IT teams that want MDR bundled in from day one rather than layered on through a separate partner ecosystem, since Sophos expanded its own MDR service as part of the same August 2026 GA that shipped XDR Powered by Secureworks. Organizations that want bundled, predictable subscription pricing over granular per-GB ingestion fees will also lean toward Sophos, trading some cost transparency for simpler budgeting. And for security teams that specifically want Secureworks’ threat intelligence lineage built into their detection content, Sophos XDR Powered by Secureworks is the only platform in this comparison that offers it natively.
Migration Guide: Moving Between Defender XDR and Sophos XDR
Switching XDR platforms mid-contract is disruptive, so most organizations plan the move around a renewal date. Here is the general sequence security teams follow regardless of which direction they are migrating.
- Audit your current detection coverage. Export existing detection rules, custom hunting queries, and automation playbooks from your current platform before touching anything else.
- Map license dependencies. If you are moving away from Defender XDR, confirm whether your Microsoft 365 E5 or E7 licensing still makes sense without ISOC, since the SIEM benefit is bundled into that tier.
- Run both platforms in parallel for 30 to 60 days. Do not cut over in one step. Dual-run the old and new EDR agents on a subset of endpoints to validate detection parity before a full rollout.
- Rebuild automation playbooks natively. Playbooks rarely port cleanly between platforms; Sophos’s prebuilt Next-Gen SIEM playbooks and Microsoft’s Defender automation rules use different logic models and need to be recreated, not copy-pasted.
- Re-point log sources feeding your SIEM. If moving to Microsoft’s ISOC, model your non-Microsoft log volume against the $2.40-per-GB ingestion rate before switching feeds, to avoid a cost surprise in month one.
- Validate retention against compliance requirements. Confirm your new platform’s retention window, 90 days for Defender data starting November 15, 2026, or your contracted Sophos tier’s retention, meets your regulatory obligations before decommissioning the old platform’s historical data.
- Migrate identity and endpoint agents in waves. Roll out new EDR agents by business unit rather than all at once, monitoring for false positives and performance impact at each wave.
- Decommission the legacy platform only after a full incident-response tabletop exercise on the new stack, to confirm your SOC can actually detect and respond using the new tooling under pressure. Teams without a documented plan should build one using a standard incident response framework before cutting over.
- Update your MDR or MXDR partner relationship. If you use a managed provider like BlueVoyant on Defender or Sophos MDR, confirm their runbooks have been updated for the specific September 2026 platform version you are landing on.
Pros and Cons of Microsoft Defender XDR
Defender XDR’s biggest strength is consolidation: ISOC genuinely removes the need to provision a separate Sentinel workspace for SIEM capability if you already hold E5 or E7 licensing, and the unified data plane simplifies cross-signal hunting in ways the KQL example above illustrates directly. Independent benchmarks back this up, with a 4.6 operational-maturity score and the highest rating in 15 of 22 Forrester criteria. The clearest weakness is cost exposure on non-Microsoft data: the $2.40-per-GB ingestion meter rewards Microsoft-native environments and penalizes organizations with heavy third-party log volume. The 90-day retention window, while clearly published, may also fall short of longer regulatory retention mandates without additional archiving. Teams comparing this against other Microsoft security stack decisions, such as the ongoing Purview DLP versus Forcepoint and Netskope evaluation, will notice the same pattern: bundled licensing economics versus best-of-breed flexibility.
Pros and Cons of Sophos XDR
Sophos XDR’s strength is platform flexibility: its modular Fusion architecture, cross-platform EDR heritage, and bundled MDR option make it a natural fit for heterogeneous environments and MSPs managing many tenants. The new Next-Gen SIEM, AI Defense, and CISO Advantage modules show Sophos investing seriously in closing the gap with larger platforms rather than standing still. The clear weakness is documented market position: a 5.0% share of the worldwide modern endpoint security market against Microsoft’s 28.6%, plus a lack of published, granular pricing transparency comparable to Microsoft’s per-GB ingestion rate. The staged, multi-month rollout to existing customers also means some Sophos tenants will be running an older version of Fusion for a while yet. This same market-share dynamic shows up across other security categories, including the Darktrace versus Vectra versus ExtraHop network detection comparison, where challenger vendors compete on depth rather than installed base.
The Verdict: Which XDR Platform Wins in 2026?
By the numbers, Microsoft Defender XDR is the stronger platform for the majority of enterprises already standardized on Microsoft 365. It holds a 28.6% market share against Sophos’s 5.0%, the highest rating in 15 of 22 Forrester Wave criteria, and the top documented operational-maturity score (4.6) in the most recent independent EDR assessment. ISOC’s bundling of SIEM into existing E5/E7 licensing also removes a cost line item that used to require a separate Sentinel purchase.
That verdict flips for specific situations. Organizations with heavy non-Windows footprints, MSPs managing many small tenants, or security teams that want simpler bundled pricing over a metered per-GB model will get more value from Sophos XDR Powered by Secureworks, especially now that Next-Gen SIEM, AI Defense, and CISO Advantage have closed real feature gaps as of the August and September 2026 GA releases. The honest conclusion is not that one platform is objectively better across every dimension; it is that Microsoft wins decisively on documented maturity and market position, while Sophos wins on flexibility for environments that do not live entirely inside the Microsoft ecosystem. Teams evaluating both should model their actual log volume against Microsoft’s $2.40-per-GB rate and request a direct quote comparison against Sophos’s bundled tiers before committing to either platform’s next renewal cycle. For broader context on how the surrounding threat landscape is shaping these purchase decisions, the latest Microsoft Patch Tuesday zero-day disclosures continue to drive urgency around faster XDR correlation.
Frequently Asked Questions
Is Microsoft Defender XDR the same as Microsoft Sentinel?
No. Microsoft Defender XDR is the extended detection-and-response layer across endpoints, identity, email, and cloud apps. Microsoft Sentinel is the standalone SIEM product. With ISOC, eligible Microsoft 365 E5 and E7 customers can get SIEM-style capability inside the Defender portal without separately provisioning a Sentinel workspace, but Sentinel still exists as its own product for organizations that need its full feature set.
How much does the Microsoft ISOC ingestion fee actually cost?
Microsoft’s published rate is $2.40 per GB for non-Microsoft data ingested into ISOC, with that meter taking effect October 1, 2026. The cost scales directly with how much third-party log volume, firewalls, cloud providers, SaaS audit trails, you pipe into the platform, so organizations should model their actual monthly log volume before assuming the feature is free.
What is Sophos XDR Powered by Secureworks?
It is Sophos’s XDR platform built on threat intelligence and detection technology inherited from Secureworks’ Taegis platform following Sophos’s acquisition. It reached general availability on August 31, 2026, alongside Sophos’s new Next-Gen SIEM and an expanded MDR service, as part of what Sophos calls the next chapter of its Fusion platform.
Which platform has better independent benchmark scores?
Microsoft Defender for Endpoint Plan 2 scored the highest documented operational-maturity rating (4.6) among assessed EDR offerings in a September-October 2026 Atlas of Security comparison, and Microsoft Defender XDR received the highest possible rating in 15 of 22 criteria in Forrester’s Q2 2024 XDR Wave. Sophos was included in the same Forrester evaluation among 11 total vendors but did not top the scored criteria, and it was not separately broken out in the Atlas of Security EDR dataset.
Do I need Microsoft 365 E5 to use ISOC?
ISOC became available starting September 23, 2026 to eligible Microsoft 365 E5 and E7 customers. Organizations on lower-tier Microsoft 365 licenses would need to confirm eligibility or upgrade their licensing to access ISOC’s bundled SIEM capability.
Can I run Sophos XDR and Microsoft Defender XDR together?
Running two full EDR/XDR agents side by side on the same endpoints is not recommended outside of a temporary migration window, since overlapping endpoint agents can conflict and create performance or detection noise. The nine-step migration sequence above, including a 30-to-60-day parallel run on a subset of endpoints, is the standard safe way to transition between the two platforms.
What is Sophos CISO Advantage?
It is one of three new modules Sophos launched alongside Next-Gen SIEM and AI Defense as part of its September 2026 Fusion expansion, aimed at giving CISOs reporting and advisory capability built directly into the platform rather than requiring a separate third-party governance tool.
Why did Microsoft’s market share grow from 18.9% to 28.6%?
IDC’s data shows Microsoft held 18.9% of the worldwide corporate endpoint security market in 2022 and 28.6% of the worldwide modern endpoint security market in 2024. The exact category definitions differ slightly between the two IDC reports, but the consistent trend is that Microsoft’s bundling of Defender capability into Microsoft 365 licensing has continued to pull enterprise customers toward its endpoint stack rather than standalone point products.
Does Sophos XDR work with non-Sophos endpoint agents?
Sophos’s XDR and Next-Gen SIEM are built to ingest third-party telemetry alongside native Sophos endpoint data, which is part of why the company expanded integrations as a headline feature of the August and September 2026 Fusion updates. The depth of any specific third-party integration still depends on what connectors Sophos has built for that particular vendor, so teams running a mixed-vendor endpoint estate should confirm connector availability for their specific stack before assuming full parity with native Sophos telemetry.
Is CrowdStrike a better option than both Microsoft and Sophos?
CrowdStrike Falcon Insight XDR tied Microsoft Defender for Endpoint Plan 2 on the 3.0 shipped-innovation score in the Atlas of Security assessment and led October 2026 AI-search recommendation coverage ahead of both Microsoft and Sophos Intercept X. That makes CrowdStrike a legitimate third option worth including in any serious evaluation, though it falls outside the direct Microsoft-versus-Sophos scope of this comparison. Organizations building a shortlist should treat CrowdStrike as a benchmark data point rather than assume either platform in this comparison is automatically the top choice in the broader EDR market.
