Performance Testing a DevDrive on Windows 11 LIVE and RAW with ZERO EDITS

[@chad_levy]

This is perfect timing! I just got a second drive for my dev machine and had intended on just storing code and my swap file but now I'll be using at least a decent chunk of it for a dev drive. We've got some projects that take several minutes to build so I'm hoping this will make a pretty big difference.

[@chad_levy]

After tinkering with it for the past hour, I'm seeing pretty decent performance (20-30%) for most build tasks. It looks like a lot of our builds are cpu-bound, at least on my dev machine which is a laptop with a 10th-gen Intel cpu. But anything file-related - dotnet clean, etc. - I'm seeing 2x+ increases. Also git is so much faster. I regularly use git worktree and adding and removing worktrees is easily 4-5x faster now.

[@michaelbrzycki]

Doing "disk stuff" always makes me uneasy. Measure twice, cut once sort of a thing!

[@Mcohen20]

glad i am not the only one

[@wadewalker25]

What about comparing windows with an excluded folder from antivirus compared to the dev drive with the exclusion?

[@winstoncarter8542]

yes, exactly thats what I thought as well. The comparison is not with same input parameters.

[@LiqdPT]

4:53 right there if you kept reading down, it says you've got 2 drives with unallocated space. Didn't even need to go into disk manager to see that. (though, yes, DM helped you determine which disk 0 and disk 1 were)

[@NotInventedHereShow]

When you tried the last time on C-drive, your nuget cache was on the D: drive, so you got some benefits from that too.

[@chad_levy]

RE: using DevDrives for TEMP folders (at 21:40), I don't know that this would be a good idea given that there's trust concerns when using DevDrives. Package caches make a lot of sense since there is some degree of trust regarding which packages you're using (hopefully) but TEMP can be used by any program.

[@shanselman]

Trust in what way?

[@BenDuguid]

Seems to me that the biggest part is the AntiVirus integration. As you state at the end, by moving your package caches (nuget, npm, ruby, composer, etc.) on to the Dev Drive as well then clones and restores should improve massively. Now i just need corporate IT to start rolling out Windows 11 and ensure their preferred AV supports trusted drives ;)

[@MrKar18]

Good luck convincing IT dept to not actively scan dev drives. They would rather let Windows slow everyone down. 😅

[@adambr8448]

​@@MrKar18yes it all depends on the layers of security you have in our environment and the risk a company is willing to take. Async scanning is more secure than folder exclusions for equivalent perf. But if your IT doesn't allow folder exclusions, then the argument is more challenging - it all depends on if you have other mitigations for potential supply chain attacks (eg: do devs only get source, packages & apps from internal catalogs that are vetted in other ways), does scheduled scans provide another layer of mitigation, etc.

[@berndeckenfels]

Yes, it only helps with defender async. In fact I opened a documentation bug a while ago go asking for clarification, since in the past ReFS was slower than NTFS and it is unclear if the devdrive wizard actually reconfigures filesystem parameters to optimize it to dev workload. I think in any case with any other malware solution it will not help much (maybe besides reducing MFT contention). Wonder how much VHDX will eat up the gain. (GitHub MicrosoftDocs windows-dev-docs 4438)

[@berndeckenfels]

@@MrKar18the point about devdrive is that you don’t have to turn it off, only run it in other mode.

[@MrKar18]

@@berndeckenfels I understand all that. If you work in enterprise, you would know. They literally operate on zero trust mode, so yeah.

[@Fade2blk9]

I'm glad that they are working to help dev productivity in terms of filesystem improvements. Unfortunately FS performance on a mounted dev drive still sucks :( It would be REALLY nice to be able to efficiently share a directory between Windows and WSL2. Do you (Scott, or anyone else for that matter) have any recommendations for improving performance in this scenario? I feel like devs with Windows machines toggling back and forth between WSL and native Windows has to be pretty common. Many dev tools just don't work well (or not at all) for windows, especially when working with containers, K8s, etc.

[@BraytinerHeggendorn]

What is prompt command history program you use? 1:59

[@MosquitoBite82]

I love how youtube cut to a commercial for painkillers just as you made your paranoid face and pressed the button to do diskstuff! 😅😅😅 Thanks for a great video by the way!

[@leszekn4008]

Hey Scott! Have you tested the same thing bu with DevDrive created as a Virtual Container instead of a new partition? Are there any differences in performance between those two options? Thanks!

[@pilotboba]

afaict you don't need to enable "developer mode" to use DevDrives. Developer mode is needed to develop native Windows apps.

[@shanselman]

I believe we tied that bit to DevDrives also to be explicit about intent

[@pilotboba]

@@shanselman I am able to create a dev drive without dev mode being enabled.

[@LaMasze]

What shell are you using in ps ?

[@shanselman]

That's PWSH with OhMyPosh as a prompt

[@LaMasze]

@@shanselmanthx :)

[@rs3800]

any plans to have that feature on (build) servers? Many corporate Windows servers also suffer from AV filters and slow disk IO...

[@AbcDef-xs8xi]

What is this zooming/arrow-ing/border-ing program you use (1:44)? Can I download it from somewhere?

[@shanselman]

Zoomit. Winget install sysinternals

[@mr.o5577]

I have a question, DevDrive vs WSL2, which one is better? Can you have your wsl inside DevDrive? If they working already on wsl why making a dev drive?

[@shanselman]

Unrelated tech. Use both separately

[@valdoimpalatorez]

My version of windows 11 is 22621.2428. I have developer mode on and full unallocated disk. I see "Create dev drive" option in windows, but have no way of actually creating a dev drive. Am I missing something?

[@shanselman]

You’re saying clicking create dev drive doesn’t do anything?

[@ChavdarIvanov4]

@@shanselman ReFS now exists only in Windows 1[01] Enterprise or Pro for workstations. Creation capability was removed from all other versions starting from 1709; they still retain read/write to ReFS capability, but not creation. Therefore, DevDrive is NOT available on the most used W11 editions.

[@valdoimpalatorez]

@@shanselman I didn't even have that option. Have installed all latest updates and am now on 22621.2506. Now it works.

[@jnobile]

It's disabled by default in group policy 😢.

[@ChavdarIvanov4]

@@shanselman 'Create dev drive' option is missing completely. Manual attempt to format a partition with ReFS also fails. So there is no group policy update, apparently the code is missing from SKUs different from Enterpreise/Workstation.

[@LiqdPT]

Hey Scott, I noticed your terminal window opens nice a quick. Since I set up Ohmyposh similar to you, it takes 2-5 seconds to load my profile. Any idea how to debug it?

[@shanselman]

Steve Lee has a performance profiler for profilers. Often folks have too much going on. He has a blog on this topic.

[@LiqdPT]

@@shanselman the only things I have explicitly in my profile are things I took out of yours (but not all of yours I don't think). Thanks, I'll look for Steve's blog

[@shanselman]

@@LiqdPTis everything on an SSD?

[@LiqdPT]

@@shanselman one surface book and one surface laptop

[@pilotboba]

I watch 99% of dev videos on 1.5x speed and always marvel at how fast their machines are... and then I remember, oh yea... :)

[@alfonsovargas8578]

Do you use external antivirus? I can find the Dev Drive protection option.

[@1roboBongoCuckooCop]

I get a 'Unable to format volume. Error: Cannot perform the requested operation when the drive is read-only (8)' when I try to create a dev drive with some unallocated space. No idea why, the drive isn't read only and doesn't show up as such in disk management. Anyone any ideas?

[@dzmitrykuzmiankou6418]

use admin rights whet try to create a dev drive

[@jasselin1]

Very interesting video Scott. Anyone know if other AV software will support DevDrives?

[@BillyONeal]

You say “only matters if disk limited” (paraphrased) but my understanding is that the point of Dev Drive is to address cpu bottlenecks caused by all the filters to talk to the disk.

[@shanselman]

I wouldn’t call those bottlenecks, but rather unnecessary overhead. Regardless the intent is to have a few layers as possible between your process and the bytes on the disk

[@mushfiqwebTV]

Hi Scott, After every update the DEV DRIVE disappears.

[@daniel.goehler]

Do you know why creating a dev drive is greyed out in Windows on Arm64 (Windows Dev Kit 2023)?

[@ankur-dhama]

May be the ReFS driver is not there for Arm yet. Do you see refs.sys file in C:\Windows\System32\drivers folder?

[@daniel.goehler]

@@ankur-dhama Thank you, refs.sys was there an I could also create a ReFS just not the dev drive. I had to update from 22631.2428 to 22631.2506 on Windows 11, then I was able to create the dev drive and now it works also on ARM. I'm not sure why Windows Autopatch doesn't install 22631.2506 on my machine.

[@adambr8448]

@@daniel.goehler - we had a group policy bug that impacted *.2428, it was fixed in *.2506.

[@AndrewDavidWilson]

What is it about dev drives that limits their use on dev directories? Why not use them everywhere?

[@shanselman]

I think they are just being conservative

[@adambr8448]

Dev Drive does not load all filter drivers, so you can run into app compat issues with some tools. Also the default security posture has Defender in Performance mode - which does Async scanning. This wouldn't be recommended for your main OS drive. Performance mode provides better security than folder exclusions without compromising perf.

[@stephanebarizien7885]

You should set up keyboard shortcuts to jump from one command output to the next to find previous results faster. And run your divisions from the PS prompt instead of using Calc 😜. I second another guy's comment that one provably shouldn't put the system-wide Temp on the Dev Drive; I'd probably go for a local override in the shell. About using unpartitioned space: beware that this eats up the space set aside by SSD overprovisioning so theoretically affects your SSD's lifespan. The PowerToys Environment Variable editor now *has* been released 😛.

[@shanselman]

Good tips!

[@moneyDev1111]

if I run a malicious repo on a dev drive that will spawn a process with a nodejs, will the dev drive save me from sending all the private stuff I have in .env files for example? What's the difference security-wise comparing to the usual NFT folder? Thank you

[@Netz0]

Nope, in fact, the dev drive might more insecure than your regular drive.

[@jorgepedraza1275]

interesting information. Any suggestions with HDD and standard hardware?

[@berndeckenfels]

HDD are unuseable with or without devdrive ,)

[@amitse]

Did you get a chance to test out HDD? ie HDD NTFS vs HDD REFS. I've a smaller SSD for OS and a bigger (cheaper) HDD for storage.

[@shanselman]

I haven’t, I’m sorry. I haven’t used an HDD in many many years. 😢

[@alan-]

Get a another small SSD for like $30 or less. 256 gb is more than enough and they cost nothing these days

I develop on a VM (win 11 guest) running in my Win 11 host. Can I make a devdrive VHD on host and mount it to guest?

[@berndeckenfels]

Should work (if not removable), but I think you need to format it from the guest to get it trusted. However I would not expect much performance improvement if you can instead turn defender off

[@keyser456]

I kept waiting for that "wow!" moment... for 28 minutes... Appreciate the effort though. :)

[@pilotboba]

So, running builds at the command line I don't think is the main "wow". I think having your Visual Studio projects on the dev drive is the real win here. Studio thrives on disk access... all the background compiling, intelisense, running extensions, launching iis express web sites, caching all access the project folder. If VS is slow, give is faster hard drive before giving it more memory or more CPU.

[@Netz0]

Just 2 suggestions I would add. The option to resize an existing volume on Windows 11 is bugged. It says 50 GB is the minimum for Dev drives, yet the only option you have on the setting's screen is the total free space on your drive. Be aware that if you do this on your main C: drive, you are now left with 0 free space left 😡 This is seriously a bug because if you go to the old Disk Management tools on Windows you can just shrink your existing drive to the desired size, example 50 GB (if that is your flavor...). Then go back to the options and you can pick the new unallocated space. Use the old Disk Partition tools and not the Win11 Dev drive wizard. Second suggestion. Do not forget to enable BitLocker on that new dev drive, by default it will not be encrypted. Great video!

[@iyke8913]

Would the Pagefile on dev drive be a good thing?

[@shanselman]

Good question!

[@berndeckenfels]

Not if it’s in a vhdx ,)

[@MontagoDK]

Seems like the biggest improvement came from AntiVirus settings...

[@imaera1]

You not being LinusTechTips is a good thing. 🤣🤣🤣

[@TeresitaChavez-z6t]

Thank

[@sulfur32066]

I was watching on the wrong numbers 😂😂😂

[@LouisDuran]

17:15 Technical terms... 😂

[@jacobstamm]

Performance Testing a DevDrive on Windows 11 using FACTS and LOGIC

[@DannyNilsson]

doing benchmarks that only runs for 1 second does not make sense. In real world would you spend the time to setup a dev drive to save 0.5 second and have a more complex setup

[@DamienSawyer]

Be warned, I tried this and during the creation of the dev drive my machine blue screened of death. I'm not sure of the SSD model but it's a fairly recent 2Tb Kingston. Looking into DISKPART in recovery mode, it appears my entire C partition is gone. Work lost, hours wasted. My fault I guess 😞

[@adambr8448]

I'm sorry this happened, I haven't seen reports of something like this happening at scale. I'm not sure which flow you used - but perhaps partition your drive into C & D volumes, both as NTFS first. And then try re-formatting D as a devdrive from the command line with "format d: /q /devdrv /v:DevDrive". If you could open a FeedbackHub issue to capture your device and hardware information and submit under Developer Platform->Dev Drive, we could try to reproduce on our end.