RAID 0 NVME Read Performance Same as Non-RAID

Caxton wrote: Thank you all for helping debug this issue. It appears the initial suggestion was AI-generated, based on the style and format in the original post that referenced "Can I use a Fedora Live CD to mount...". While it was helpful to some extent, the proposed solution ultimately did not work as expected due to several limitations. Fedora LiveCD/USB environments come in various versions, and commands can behave differently depending on the specific combination of version and environment used. For example, the following command failed when executed in the Fedora 42 Live environment (booted via USB media): sudo dnf install dmraid The failure message was: "failed to resolve the transaction" and "no match for argument dmraind:" To provide additional context: Fedora 42's Live CD/USB environment does not include `dmraid` by default, nor does it allow installation via the above command. A subsequent search within the booted environment, executed as follows: sudo dnf search dmraid ...returned: "no matches found." The search was performed after the install command failed, simply to confirm whether the `dmraid` package might already exist in the environment?�but it does not. So, since this approach appears to be a dead end (at least thus far), are there any alternative methods to non-destructively test RAID 0 read performance? For reference, when testing in the native environment (Windows 11), the issues are consistently related to read commands, irrespective of hardware connection configurations. However, write commands only produce at RAID 0 performance thresholds when one SSD is connected directly to the CPU bus and the other is on the chipset bus. These findings have been consistent across all tested configurations.

im really am sorry, i literally asked the chatbot that in next prompts and it assured me that fedora should be the most straight forward to do that and wont need internet connection. Personally i just use arch



below are the results i get on a single kc3000,nv2 drives:

> sudo hdparm -Tt /dev/nvme0n1p4 /dev/nvme0n1p4: Timing cached reads:   57590 MB in 1.99 seconds = 28908.02 MB/sec Timing buffered disk reads: 7560 MB in 3.00 seconds = 2519.50 MB/sec mm@desktop ~ > sudo hdparm -Tt /dev/nvme1n1p5 /dev/nvme1n1p5: Timing cached reads:   58770 MB in 1.99 seconds = 29503.06 MB/sec Timing buffered disk reads: 8126 MB in 3.00 seconds = 2708.63 MB/sec

Edited by M440 - 30 Apr 2025 at 2:25pm

NDRE28 wrote: I am running my RAID-0 setup on an AMD AM5 platform. One of my SSDs is connected directly to the CPU, while the other 2 are connected to the chipset. OS: Windows 11 Enterprise v24H2. In my case, everything runs as expected, in terms of performance. RAID-0 did improve the transfer speeds.

Regarding RAID 0 performance, are you achieving close to 2x read/write speeds compared to a single SSD? This presumes at least one array is in a 2x NVMe/SSD RAID 0 config. Ideally, the performance should approach the theoretical maximum achievable across the bus and scale as additional, identical SSD's are added to a RAID 0 array.

I?™m particularly interested in whether you?™re obtaining optimal results, especially in comparison to my own setup. Interestingly, I previously purchased (and later returned) an 8TB WD NVMe drive that exhibited slower performance than a single Samsung NVMe. Theoretically, it should have been significantly slower than two Samsung NVMe drives configured in RAID 0, yet the actual performance difference was negligible.

At present, the results seem inconclusive. I?™d love to hear your insights on this.

My primary goal is to build a RAID 0 array using two Samsung 990 Pro 4TB NVMe SSDs, resulting in a single 8TB volume optimized for read/write performance in line with the hardware capabilities?”specifically, nearly doubling bandwidth for reads and writes. Theoretically, this setup should achieve read speeds of approximately 14,900 MB/s and write speeds of about 13,800 MB/s on par with Gen 5x4 single non-RAID NVMe's

However, RAID 0 read performance has failed to effectively utilize parallelization, with read speeds mimicking single-drive performance as measured by both Windows 11?™s winsat tool and CrystalDiskMark. For instance, across three CrystalDiskMark test runs?”each consisting of five repetitions?”the average read performance was 7,211 MB/s, irrespective of the slot configuration.

Interestingly, write performance closely aligned with real-world RAID 0 expectations, reaching approximately 13,748 MB/s when utilizing the M2_1 and M2_2 slots with PCIe Gen 5x4 with the Gen 4x4 configuration. In contrast, other connection and bus combinations delivered suboptimal write performance, averaging around 6,961 MB/s. This includes all tested physical configurations, such as M2_2 with M2_3 (PCIe Gen 4x4) and M2_3 with M2_4 (PCIe Gen 4x4).

Thank you all for helping debug this issue.

It appears the initial suggestion was AI-generated, based on the style and format in the original post that referenced "Can I use a Fedora Live CD to mount...". While it was helpful to some extent, the proposed solution ultimately did not work as expected due to several limitations. Fedora LiveCD/USB environments come in various versions, and commands can behave differently depending on the specific combination of version and environment used.

For example, the following command failed when executed in the Fedora 42 Live environment (booted via USB media):

sudo dnf install dmraid

The failure message was:
"failed to resolve the transaction" and "no match for argument dmraind:"

To provide additional context: Fedora 42's Live CD/USB environment does not include `dmraid` by default, nor does it allow installation via the above command. A subsequent search within the booted environment, executed as follows:

sudo dnf search dmraid
...returned:
"no matches found."

The search was performed after the install command failed, simply to confirm whether the `dmraid` package might already exist in the environment?”but it does not.

So, since this approach appears to be a dead end (at least thus far), are there any alternative methods to non-destructively test RAID 0 read performance?

For reference, when testing in the native environment (Windows 11), the issues are consistently related to read commands, irrespective of hardware connection configurations. However, write commands only produce at RAID 0 performance thresholds when one SSD is connected directly to the CPU bus and the other is on the chipset bus. These findings have been consistent across all tested configurations.

I will give that a go and reply with results. Great suggestion!

the nvme drives firmware is updated?

this is BIOS/UEFI RAID?

anyway i would blame:
-os/drivers
-nvme drives firmware
-motherboard/bios/hardware