Poor RAID1 RST/VMD performance with NVME drives

[5urg3]

I have:

HP Z2 Mini G9
Core i5 12500
64GB DDR5 ECC 5600 RAM
Windows 11
2x 1TB Crucial T500 1TB drives in raid 1 (these drives have a Phison PS5025-E25 controller and 1GB DRAM cache, they are Gen 4)
Using latest bios from HP (Nov ‘23)

Individually the drives perform as advertised with large xfer size high queue sequential IO (reads at around 7GB/s, writes at around 5-6 GB/s).

When using the Intel RAID1 on windows 11 (raid volume was created using the option rom of RST VMD controller) with 64 kb stripe size, read performance is roughly half of one individual drive, tested with file system on Windows 11, large block sequential read high queue

Large block seq high queue Write performance is abominable, even with write back cache enabled on the RAID volume

FYI I also notice there is a bug in the windows optane / RST gui app, as it greys out enabling write back cache for some reason, though you can still enable it in Windows device manager or disk management

The most it will do in writes is around 2 GB/s and then it just tanks when the cache trashed to less than 500 MB/s

Read speed goes just above 4GB/s on select IO profiles

This occurs using IOmeter to generate IO as well other benchmarking apps

I haven’t used Intel RST in a long time, is this expected behavior?

It’s really really bad

The only other thing I thought to check is the PCIe speed of the drives and HWinfo shows it as gen 4x4 for both, so that’s definitely not the issue

To be completely honest I need the redundancy MORE than I need the speed, but this computer only has two PCIe SSD slots, so I can’t just get a larger single drive and use that for faster access to temporary data, and keep my slower boot volume mirror — unfortunately

[H_Mlysgeek]

Hello there, 5urg3...

The performance issues you're experiencing with the Intel RAID1 configuration on your HP Z2 Mini G9 are indeed concerning, especially considering the high-quality components and the expected performance levels of your setup. It's not typical for RAID1 to cut read speeds in half compared to a single drive, nor is it normal for write speeds to drop significantly when the write-back cache is enabled.

The fact that you're seeing such a drastic reduction in performance could be indicative of several potential issues:

1. Driver or Firmware Issues: It's possible that there's a mismatch between the RAID controller firmware and the drivers you're using, leading to suboptimal performance. Ensuring that both are up to date is crucial.
2. RAID Configuration: The stripe size or other RAID parameters might not be optimized for your specific workload. Tweaking these settings could potentially improve performance.
3. Software Bug: The bug you've noticed in the RST GUI app could be part of a larger issue affecting the overall performance of the RAID array.
4. Hardware Limitations: While the PCIe speed is not the issue, there could be other hardware-related limitations or conflicts at play.

Given the complexity of RAID systems and the multitude of factors that can affect performance, it's challenging to diagnose the exact cause without further investigation.

Your need for redundancy is absolutely valid, and it's unfortunate that the performance is not meeting expectations. If the troubleshooting steps don't lead to a satisfactory resolution, you might have to consider a different RAID setup or even a hardware RAID solution that could offer better performance while still providing the redundancy you require. Remember to back up all important data before making any changes to your RAID configuration.

Hope this helps....

Regards,

Harry

[5urg3]

That response reads like it was written by chat GPT, lol…

Anyway, I found out that RST VMD isn’t even supported on Linux. I didn’t know this. I had always just assumed since Intel has such a good relationship with the kernel team, that it would be.

I had intended to dual boot this system — so now it appears that I have to make a choice…

I benchmarked the performance of md using Ubuntu Jammy, and it is amazing, there are no problems with the same drives in an identical RAID1 config

So, I guess I have to go through and see just how many of my windows apps and games will run under Wine and if there are any compatibility issues