Dev Drives?

garlin said:

Dev Drives are a form of ReFS volumes designed for application developers to host their code repositories on them. Compiling software requires creating a lot of temp files, which are later discarded, and the default Defender real-time settings can negatively impact the compiler's performance. As a compromise, you migrate your dev activities to a Dev Drive, and Defender promises to be less aggressive in scanning the volume. This only happens because Defender knows why Dev Drives exist in the first place.

If you're not a dev, then Dev Drives don't need to be created.

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Protect Dev Drive using performance mode - Microsoft Defender for Endpoint

Learn how to manage, configure, Microsoft Defender Antivirus performance mode for developers who use Dev Drive.

learn.microsoft.com

Performance mode compared to real-time protection​

By default, to give the best possible performance, creating a Dev Drive automatically grants trust in the new volume. A trusted Dev Drive volume causes real-time protection to run in a special asynchronous performance mode for that volume. Running performance mode provides a balance between threat protection and performance. The balance is achieved by deferring security scans until after the open file operation has completed, instead of performing the security scan synchronously while the file operation is being processed. This mode of performing security scans inherently provides faster performance, but with less protection. However, enabling performance mode provides significantly better protection than other performance tuning methods such as using folder exclusions, which block security scans altogether.

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garlin said:

For those interested, here's a more complete explanation:

Protect Dev Drive using performance mode - Microsoft Defender for Endpoint

Learn how to manage, configure, Microsoft Defender Antivirus performance mode for developers who use Dev Drive.

learn.microsoft.com

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