Dev Drive in Windows 11 is the kind of under-the-radar feature that quietly changes how the OS treats storage: formatted with Microsoft’s Resilient File System (ReFS) and tuned for developer workloads, a Dev Drive can also deliver measurable gains for certain gaming scenarios — but it comes with trade‑offs you must understand before moving your library.
Microsoft designed ReFS (Resilient File System) to prioritize data integrity, scalability, and reliability. Unlike NTFS, ReFS uses checksums for metadata, allocation‑on‑write (copy‑on‑write) semantics, and other on‑disk optimizations to reduce exposure to corruption and to improve throughput for large, metadata‑heavy workloads. Those same mechanisms are the foundation for Dev Drive: a ReFS volume created and managed with specific performance and trust settings aimed at developer tasks like large repository operations, package caches, and build output.
Microsoft’s Dev Drive is not simply “ReFS on a different letter.” It bundles three important things:
Microsoft’s own developer messaging and early engineering posts referenced up to ~30% improvements in targeted I/O developer scenarios when using Dev Drive optimizations, but those are workload‑specific figures and not a universal guarantee for games. In short: some repositories and copy‑heavy tasks show large gains; most games on NVMe will not.
Caveat: community and independent testing of Dev Drive for gaming remains limited. That makes MakeTechEasier’s numbers useful but not definitive across every title, hardware mix, or anti‑cheat environment. Treat published percentage improvements as indicative, not absolute, and benchmark on your hardware.
Moving games to a Dev Drive is a pragmatic, low‑risk experiment that can yield useful load‑time and install‑time improvements on the right hardware and with the right titles. The gains are real for some workloads — especially on SATA SSDs and for heavy file‑copy jobs — but they’re not universal, and they come with trade‑offs in security, compatibility and features. Test on your system, keep good backups, and treat the Dev Drive as a specialized tool: powerful when used properly, problematic when used blindly.
Source: Make Tech Easier Here's Why You Should Move Games to a Dev Drive in Windows - Make Tech Easier
Background / Overview
Microsoft designed ReFS (Resilient File System) to prioritize data integrity, scalability, and reliability. Unlike NTFS, ReFS uses checksums for metadata, allocation‑on‑write (copy‑on‑write) semantics, and other on‑disk optimizations to reduce exposure to corruption and to improve throughput for large, metadata‑heavy workloads. Those same mechanisms are the foundation for Dev Drive: a ReFS volume created and managed with specific performance and trust settings aimed at developer tasks like large repository operations, package caches, and build output.Microsoft’s Dev Drive is not simply “ReFS on a different letter.” It bundles three important things:
- File system behavior tuned for developer patterns (fast metadata and small‑file I/O).
- Block‑cloning and copy‑on‑write advantages surfaced to the Windows copy engine.
- A security/scan model that treats the Dev Drive as “trusted” by default and enables Defender to scan files asynchronously for throughput improvements.
How ReFS and Dev Drive Work — The Technical Nuts and Bolts
ReFS fundamentals (why it behaves differently than NTFS)
ReFS uses B+‑tree on‑disk structures for metadata and (optionally) file data integrity streams, and it stores 64‑bit checksums for critical filesystem structures. The allocation‑on‑write model avoids in‑place metadata edits, which reduces risk of “torn writes” and improves resiliency during crashes or power loss. Because metadata operations can be cheaper and less blocking, workloads that open, enumerate, and manipulate many small files can see better throughput on ReFS compared with NTFS.Block cloning and copy‑on‑write (what saves time)
Block cloning allows ReFS to implement logical copies as metadata operations: rather than physically copying every byte, the file system creates references so multiple files can share the same logical clusters until a write modifies one. This conversion of an expensive read/write copy to a lightweight metadata change reduces I/O and speeds duplication or patch operations dramatically — and is a cornerstone of Dev Drive’s performance claim. Microsoft recently surfaced block‑cloning support more prominently in client Windows releases, and engineering tests show large reductions in copy time for big files.Defender asynchronous scanning (the security trade)
To avoid per‑file blocking latency, Dev Drive volumes are, by default, designated as trusted and subject to asynchronous Microsoft Defender scans. That means files are allowed to open immediately while Defender completes an in‑background scan. The outcome is reduced file‑open latency — useful for build systems and game asset loads — but it’s a deliberate security trade: untrusted binaries stored on a Dev Drive gain a window where they can execute before the scan finishes. Microsoft documents the trust/designation model and administrators can manage these settings, but the default is optimized for performance.Why a Dev Drive Can Help Gaming (and when it won’t)
The situations where you’ll feel a difference
- Games that depend on thousands of small files (resource manifests, texture shards, script files) can benefit because ReFS handles metadata and many small I/O operations more efficiently than NTFS under certain loads. This can shorten initial scene loads or asset streaming stalls when storage was the limiting factor.
- Large install/patch jobs (copying or unpacking multi‑GB files) can complete faster thanks to block‑cloning and copy‑on‑write optimizations when they are used by the platform or installers.
- Systems where Windows Defender real‑time file‑open latency is the bottleneck will see improved apparent responsiveness because Dev Drive defaults to asynchronous scanning for trusted volumes.
When you should not expect miracles
- On modern NVMe drives with very low latency and high IOPS, the real‑world gains for gameplay are typically negligible. NVMe’s baseline is already so fast that filesystem micro‑optimizations produce little perceptible change for asset streaming during play.
- If your bottleneck is GPU, CPU, network, or game engine design (not storage), moving files to a Dev Drive will not increase frame rates or remove CPU‑bound stutters.
- Anti‑cheat systems or mod tools that rely on NTFS quirks (compression, specific hardlink behaviors) may break or warn on ReFS volumes. Expect the occasional compatibility snag, especially with older or tightly coupled anti‑cheat modules.
What the Benchmarks and Tests Say — Reality Check
MakeTechEasier tested several games on a SATA SSD (roughly 530 MB/s read/write) and reported initial load time improvements of ~5–16% for titles such as Red Dead Redemption 2, ARK, Albion Online, and Call of Duty when installed on a Dev Drive versus the same SATA SSD formatted as NTFS. Those gains were measured after a fresh restart and were most noticeable on initial level loads rather than sustained in‑game performance. That single‑site test suggests measurable wins for SATA SSD setups, while emphasizing that NVMe setups saw negligible differences in real practice.Microsoft’s own developer messaging and early engineering posts referenced up to ~30% improvements in targeted I/O developer scenarios when using Dev Drive optimizations, but those are workload‑specific figures and not a universal guarantee for games. In short: some repositories and copy‑heavy tasks show large gains; most games on NVMe will not.
Caveat: community and independent testing of Dev Drive for gaming remains limited. That makes MakeTechEasier’s numbers useful but not definitive across every title, hardware mix, or anti‑cheat environment. Treat published percentage improvements as indicative, not absolute, and benchmark on your hardware.
Drawbacks, Risks and Compatibility Concerns
Security tradeoffs — don’t ignore them
By design a Dev Drive is treated as trusted for performance reasons, which enables asynchronous scanning behavior. That reduces latency but increases risk if you place unvetted content (mods, cracked executables, random downloads) on the drive. Microsoft and security reporters emphasize that Dev Drive performance mode is not a global safety guarantee — it is a pragmatic balance for developer artifacts that are expected to be trusted. You can change this behavior in Windows Security, but the default is performance‑oriented.Missing NTFS features and consumer conveniences
ReFS — in its client variant — intentionally omits some NTFS consumer features (historically: per‑file compression, EFS file encryption, some quota features). That can break workflows that depend on compression or encryption at the filesystem level. If you rely on NTFS compression, EFS, or specialized third‑party backup/utility tools, expect functional gaps. Some community threads report tooling and migration issues when mixing ReFS and older toolchains.Anti‑cheat and mod tool friction
There are anecdotal reports and scattered compatibility cases where anti‑cheat systems or mod managers behave differently (or outright fail) on ReFS volumes because the tools expect NTFS semantics. While these cases are not universal, they are important for multiplayer or cheat‑sensitive titles: if you rely on online play protected by strict anti‑cheat checks, test carefully before moving your live install to a Dev Drive.Portability and management limits
Dev Drives created as VHD/VHDX files are portable as files, but Microsoft explicitly warns against copying a Dev Drive VHD between machines and continuing to treat it as a trusted Dev Drive on the destination without re‑creating trust and configuration. The Dev Drive designation is attached at format time and certain trust and filter driver behaviors are host‑specific. Always treat VHD transfer as a backup/transport mechanism — not a drop‑in trusted volume on another host.How to Create a Dev Drive — Practical Steps (quick how‑to)
You don’t have to convert your system drive or abandon NTFS systemwide. Create a separate Dev Drive, move a few games, and test. The minimum Dev Drive size is 50 GB and you’ll need administrative privileges.- Open Settings → System → Storage → Advanced storage settings → Disks & volumes → Create Dev Drive. Follow the wizard to either create a VHDX or format free space.
- If resizing an existing partition, choose Resize an existing volume and ensure unallocated space is ≥50,000 MB (50 GB).
- Choose VHDX (recommended) or VHD, and pick dynamic vs fixed (dynamic is generally more flexible). VHDX supports up to 64 TB and offers better resiliency for native‑virtual workflows.
- Once created, format the new volume as ReFS (the Dev Drive wizard does this) and assign a drive letter. You can delete the Dev Drive later from the same Disk & volumes UI.
- Format D: /DevDrv /Q
- PowerShell: Format-Volume -DriveLetter D -DevDrive
(These require Administrator and match Microsoft’s documented examples.)
A Practical Playbook: When and How to Move Games
Recommended pattern
- Keep system software and core installers on C: where NTFS semantics and system protections are standard.
- Move heavy game data that you trust (official installs, non‑risky DLC) to the Dev Drive to test improvements in load times and install/patch throughput. Use your game launcher’s multi‑folder support (Steam library folders, Epic/EA/GOG settings) to place installations on the Dev Drive rather than hacking installs.
- For games with mod ecosystems or unknown third‑party binaries, avoid placing mod‑downloaded content on a trusted Dev Drive unless you explicitly manage the security tradeoff and scan those files manually.
Short testing checklist (do this before committing a full library move)
- Pick 2–3 representative titles (one open‑world, one small‑files title, one patch‑heavy title).
- Record baseline metrics: initial load times, in‑game asset‑streaming stalls, and install/patch time on your current NTFS volume (use in‑game benchmarks or a stopwatch for load screens).
- Create a Dev Drive (50–100 GB dynamic VHDX if you want portability). Move one title and re‑test the same metrics.
- Compare results. If gains are meaningful for your play habits, move additional titles. If not, revert — the Dev Drive can be deleted and the VHDX removed without touching your system drive.
Troubleshooting and Best Practices
- If an anti‑cheat error occurs after moving a game, move it back to NTFS and verify with the publisher’s support — don’t assume the Dev Drive is the culprit without testing. Some anti‑cheat vendors have historically been strict about filesystem semantics.
- If you need encryption, remember that ReFS historically did not support per‑file EFS and some consumer compression/encryption features are missing; consider BitLocker on the host volume (VHDs inherit host BitLocker behavior) if full‑disk encryption is required.
- If you observe odd “RAW” errors or unexpected issues with ReFS volumes after major Windows updates, treat them as higher‑risk than NTFS until you verify compatibility on your build — community threads show occasional version mismatches in specific scenarios. Keep good backups.
- If you use dynamic VHDX, remember the VHDX file is a single point of failure — back up the VHDX file itself as you would any critical image.
Verdict — When to Move Games to a Dev Drive
- Consider a Dev Drive if:
- You primarily use a SATA SSD or older storage where small‑file and metadata performance is the limiting factor.
- You run games or tools that perform many small file reads or large copy/unpack operations and you want faster installs/patches.
- You’re comfortable managing the security tradeoff (or will lock down what goes on the Dev Drive).
- Avoid a Dev Drive if:
- Your primary storage is a high‑end NVMe where gains are likely negligible.
- You rely on NTFS‑specific features (per‑file compression, EFS) or on anti‑cheat systems that have known issues with ReFS.
- You keep untrusted third‑party mods or random downloads in your game folders — the asynchronous scanning model widens the risk window.
Final Recommendations (step‑by‑step)
- Start small: create a dynamic VHDX Dev Drive of ~100 GB and move one or two trusted games to it.
- Measure before and after for load times, install/patch time and perceived stutter. Use in‑game benchmarks when available.
- If you accept the security tradeoff, adopt a policy: only vendor‑signed binaries or verified game installs go on the Dev Drive; keep mods and downloads on a quarantined NTFS volume.
- Keep backups of VHDX files (or the original install) and test anti‑cheat functionality immediately after moving a title. Revert to NTFS if you see instability.
Moving games to a Dev Drive is a pragmatic, low‑risk experiment that can yield useful load‑time and install‑time improvements on the right hardware and with the right titles. The gains are real for some workloads — especially on SATA SSDs and for heavy file‑copy jobs — but they’re not universal, and they come with trade‑offs in security, compatibility and features. Test on your system, keep good backups, and treat the Dev Drive as a specialized tool: powerful when used properly, problematic when used blindly.
Source: Make Tech Easier Here's Why You Should Move Games to a Dev Drive in Windows - Make Tech Easier
