RAID 5 VMD RST Poor Writting performance / Z790

[OptimusDark]

Hello,

I recently bought a Z790 system and created a RAID 5 volume with 3 HDD.

I have 3 identical and brand new WD HDD.

Each individual disk have good performace. Using Diskmark it reaches 280Mb/s for both SEQ1MQ1T1 & SEQ1MQ8T1 writting test.

When I create a 3x RAID 5 volume the SEQ1MQ8T1 is measured at 218Mb/s (less than a single disk)  even worse the SEQ1MQ1T1 drops to 22Mb/s.

When I copy from local non RAID disk large files, it confirms 20Mb/s in real life data transfer... It can drop sometime to 5Mb/s and during few seconds to less than 1mb/s.

When I check the task manager, I can see that the drive is at 100%. 500ms of response time and between 0 et 60Mb/s of data transfer rate.

Strangely, Only one core is often at 100% when copy is in progress.

The problem is even worse when copying from network.

I installed all latest drivers (intel chipset, VMD/RST 13th gen) and MB BIOS is up to date.

I tried Windows 11 public releases as well as insiders (up to beta channel), the behaviour is the same.

I'm affraid that the problem could be between intel driver & Microsoft way of managing storage system cache...

Do you have any clue ?

Thanks for your help.

PS: I've attached the diskmark results (individual disk & RAID 5 volume results) and SSU infos

[Steven_Intel]

Hello OptimusDark,

Thank you for posting on the Intel® communities.

I am sorry you are having issues with Intel® Rapid Storage Technology (Intel® RST). I will be glad to assist you.

In order to investigate more about this behavior, please provide the following information:

• Did you install the RST driver version 19.5.0.1037 from Gigabyte page (https://www.gigabyte.com/Motherboard/Z790-AORUS-MASTER-rev-10/support#support-dl-driver-sataraidahci), or the RST driver version 18.6.1.1016 from Intel page(https://www.intel.com/content/www/us/en/download/19512/intel-rapid-storage-technology-driver-install...)?
• What is the model of the WD HDDs?

Look forward to hearing back from you.

Best regards,

Steven G.

Intel Customer Support Technician.

[OptimusDark]

Hello Steven,

Thanks for your feedback.

I tried both the official Gigabyte driver that you mentioned 19.5.0.1037 and the latest driver found on the intel site 19.5.1.1040 (https://www.intel.com/content/www/us/en/download/720755/intel-rapid-storage-technology-driver-instal...). In both case same behavior.

The model of HDD is WD201KRYZ 18TB.

I've contacted Gigabyte : they confirmed the behaviour and told me that it is normal. They confirmed the same behavior on an ASUS platform.

Best regards.

[Steven_Intel]

Many thanks for your detailed response.

By any chance did Gigabyte provide any recommendations to solve the issue, or is this something they expected to happen and consider there is no issue whatsoever?

Best regards,

Steven G.

Intel Customer Support Technician.

[OptimusDark]

No recommandations at all from Gigabyte.

Did you have the chance to transfer this case to the engineering team ?

This behaviour is easily reproducible. Same behaviour with HDD and also with NVME SSD drive.

Thanks.

[Steven_Intel]

Many thanks for your response.

We will keep working on this. As soon as I have an update, I will let you know.

Best regards,

Steven G.

Intel Customer Support Technician.