Slow IO Performance Benchmark

Creating a bug report/issue

I have an issue with multiple mounted storage devices (sd card, NVMe, and external SSD), now all of them are showing low read and write speeds in Diet Pi benchmarks (and hdparm).

Did anyone experience the same issues?
Do you know how I can troubleshoot this issue?

Any help would be much appreciated, Thanks!

Required Information

  • DietPi version | 8.20.1
  • Distro version | bookworm
  • Kernel version | Linux DietPi 5.10.110-rockchip-rk3588 #23.02.2 SMP Fri Feb 17 23:59:20 UTC 2023 aarch64 GNU/Linux
  • Architecture | arm64
  • SBC model | Orange Pi 5 (aarch64)
  • Power supply used | 5V 4A
  • SD card used | SanDisk ultra

Steps to reproduce

  1. DietPi-Config
  2. Tools
  3. Benchmarks
  4. Custom Filesystem
  5. Select the relevant mounted drive (sd card, NVMe, External SSD)

Expected behavior

The read and write speeds are expected to be much faster than the given benchmark results.

Actual behavior

Benchmark results

sd card class 10:
read 10 MiB/s write 10 MiB/s

Western Digital SN740 M.2 NVMe 2242 PCIe4.0x4 SSD:
read 378 MiB/s write 250 MiB/s
Seagate basic 2TB SSD:
read 29 MiB/s write 27 MiB/s

at least for SD (Slowest) card and NVMe (Fastest) your data seems to fit some benchmark data DietPi-Survey statistics

On the Orange Pi 5 the M.2 slot is PCIe 2.0 with only one lane, which is theoretically ~500 MB/s.
So this looks fine, considering overhead etc.
In this review they are getting only 365.23 MB/s with M.2.

But the USB speeds are indeed a bit low, about have of USB 2.0 speeds :thinking:
In the review I mentioned earlier they also say the color coding of the USB ports is wrong, even on the website it says the left on (which is white) is 3.0 and the two on the right side are 3.0 (top) and 2.0 (bottom), so maybe you can check the cabling.
Also we can investigate with lsusb -t which protocoll the device is using to communicate via USB.

I ran another Diet Pi benchmark, just this time on a larger file size instead of the 100mb recommendation, a 5000mb one. And the results differ.

Benchmark results

sd card class 10:
read 10 MiB/s write 10 MiB/s

Western Digital SN740 M.2 NVMe 2242 PCIe4.0x4 SSD:
read 389 MiB/s write 354 MiB/s

Seagate basic 2TB SSD:
read 134 MiB/s write 122 MiB/s

The sd card results are still too low which is strange, so I changed the rootFS from the sd card to the NVMe card, now that Diet Pi runs from the NVMe, everything runs smoothly without any cpu_iowait warnings.

Thanks for the info and assistance, that focused me on the solution.

Why not booting of NVMe completely and remove SD card :wink:

This is exactly what I’ve done. :wink: