Romex Software Forum

fsutil bypassio state /v c:
fsutil bypassio state /v d:
Any advice for those messages?

I have turned off the "Enable Write-Defer" in PrimoCache and now I have two other drivers giving me issues. At least it's not PrimoCache...
iaVROC.sys and iaStorE.sys

SoNic wrote: ↑Mon Apr 17, 2023 8:55 pm I have turned off the "Enable Write-Defer" in PrimoCache and now I have two other drivers giving me issues. At least it's not PrimoCache...
iaVROC.sys and iaStorE.sys

For iaStorE.sys, if you have an Intel CPU from 11th to 13th, there are new drivers that support DirectStorage:
https://community.intel.com/t5/Rapid-St ... -p/1406777
https://www.intel.com/content/www/us/en ... forms.html

You must be on Windows 11 22H2 to get the DirectStorage/BypassIO compatibility.

If a logical volume is cached by PrimoCache with defer-write enabled, bypassIO requests to that volume will be blocked by PrimoCache. Because DirectStorage bypasses all intermediate drivers such as PrimoCache and directly reads from the disk, the deferred write-data may still be in the cache and has not been written to the disk, so the data read by DirectStorage may not be the latest, resulting in inconsistency.
viewtopic.php?p=17712#p17712

PS. the reason information in the command output is provided by the driver which blocks BypassIO. So here you see "Volume with write-back caching is not supported" referring to PrimoCache, not Windows.

Support wrote: ↑Tue Apr 18, 2023 2:07 am If a logical volume is cached by PrimoCache with defer-write enabled, bypassIO requests to that volume will be blocked by PrimoCache.

That makes sense, and I saw that disabling the defer-write in PrimoCache, indeed seems to pass the compatibility.
Only to be locked by other drivers...

vlbastos wrote: ↑Tue Apr 18, 2023 1:18 am For iaStorE.sys, if you have an Intel CPU from 11th to 13th, there are new drivers that support DirectStorage:
https://community.intel.com/t5/Rapid-St ... -p/1406777
https://www.intel.com/content/www/us/en ... forms.html
You must be on Windows 11 22H2 to get the DirectStorage/BypassIO compatibility.

I am on an unsupported platform, Xeon W-2155 (Skylake-W, 7th gen i9 equivalent). I guess I would need modded and signed drivers for that. Meah... It's all marketing I guess.

SoNic wrote: ↑Tue Apr 18, 2023 10:48 am I am on an unsupported platform, Xeon W-2155 (Skylake-W, 7th gen i9 equivalent). I guess I would need modded and signed drivers for that. Meah... It's all marketing I guess.

You know, after I learned I can't use defer writes with DirectStorage/BypassIO, I chose defer writes. So much better performance overall, DirectStorage/BypassIO isn't even being adopted anywhere other than Forspoken (which seems to be a flop).

There's the bluescreen/crash risk (being on a laptop, the risk of power outtage is very low), but setting wait time to 1 (and soon to 0, hopefully) and running Windows 11 22H2 without any problems for a good time gave me a lot of confidence on defer writes.

I'm running a 2GB cache on a RAID-0 volume (2x 512GB 980 Pro OEM nvmes), getting about 20% cache hit rate with day to day usage, and disk writes are only 80% overall, which means I'm saving 20% of the lifespan of my nvmes. Better than DirectNotUsedAnywhereStorage. Performance is outstanding:

I have an UPS for my desktop so I am not worried about power loss either. I put it back to write-defer, at 10 seconds.
I have 64GB RAM in the system, so I can be more generous with my RAM allocation - 8GB plus 1GB overhead...
You could allocate more memory for writes than reads and extend the life of your SSDs even more.