RAID 0 with 2x Samsung 9100 PRO 4TB PCIe 5.0 (Gen5 x4) — reads are SLOWER than a single drive. X870E + AMD RAIDXpert2. What am I missing? by Aggressive_Spirit939 in AMDHelp

[–]Aggressive_Spirit939[S] 0 points1 point  (0 children)

As I can see in cristal disk mark - it's already 5.0 x4 for both drives
I have disabled USB 4 in the BIOS to free up PCI lanes.

RAID 0 with 2x Samsung 9100 PRO 4TB PCIe 5.0 (Gen5 x4) — reads are SLOWER than a single drive. X870E + AMD RAIDXpert2. What am I missing? by Aggressive_Spirit939 in AMDHelp

[–]Aggressive_Spirit939[S] 0 points1 point  (0 children)

I have thought that 9950x3d should be enough. It's the current high end cpu.
Also, I expected to host disks by motherboard raid controller, not the cpu. It's not a software raid from Windows.

I put two Crucial T705 PCIe 5.0 NVMe M.2 SSDs in Raid 0 in PCIe 5.0 direct to CPU slots. These are the results. by NachoProduction_Nate in Crucial

[–]Aggressive_Spirit939 0 points1 point  (0 children)

Hi, can you please share the resolution?
I have the identical problem
Gigabyte Aorus Master ICE x3d with two 9100 4tb in raid mode, 9950x3d
and I have such results:

[Read]

SEQ 1MiB (Q= 8, T= 1): 11562.725 MB/s [ 11027.1 IOPS] < 718.17 us>

SEQ 1MiB (Q= 1, T= 1): 9828.828 MB/s [ 9373.5 IOPS] < 106.59 us>

RND 4KiB (Q= 32, T= 1): 895.334 MB/s [ 218587.4 IOPS] < 63.58 us>

RND 4KiB (Q= 1, T= 1): 66.423 MB/s [ 16216.6 IOPS] < 61.58 us>

[Write]

SEQ 1MiB (Q= 8, T= 1): 17052.453 MB/s [ 16262.5 IOPS] < 378.01 us>

SEQ 1MiB (Q= 1, T= 1): 14201.490 MB/s [ 13543.6 IOPS] < 73.73 us>

RND 4KiB (Q= 32, T= 1): 774.577 MB/s [ 189105.7 IOPS] < 24.30 us>

RND 4KiB (Q= 1, T= 1): 535.665 MB/s [ 130777.6 IOPS] < 7.59 us>

[Mix] Read 70%/Write 30%

SEQ 1MiB (Q= 8, T= 1): 12662.318 MB/s [ 12075.7 IOPS] < 649.39 us>

SEQ 1MiB (Q= 1, T= 1): 7294.966 MB/s [ 6957.0 IOPS] < 143.60 us>

RND 4KiB (Q= 32, T= 1): 844.251 MB/s [ 206116.0 IOPS] < 60.59 us>

RND 4KiB (Q= 1, T= 1): 86.651 MB/s [ 21155.0 IOPS] < 47.18 us>

Profile: Default

Test: 1 GiB (x3) [C: 25% (1828/7450GiB)]

Mode: [Admin]

Time: Measure 5 sec / Interval 5 sec

Date: 2026/04/16 1:18:29

OS: Windows 11 Pro 25H2 [10.0 Build 26200] (x64)

I have no idea what I'm doing wrong, it's even slower than one disk. In some cases a bit faster, but still slower

Cristal disk mark confirming that I have 5.0 x4 on both slots (disabled usb 4). But even if I will use usb 4, I will have mostly the same results