Slow NVMe speeds compared to VF2 Arch

[danboid]

I am running starfive-jh7110-202306-nvme-minimal-desktop.img on a VF2 1.3b with the latest official firmware and uboot.

If I run

# hdparm -t /dev/nvme0n1

Under the VF2 Arch Linux port (cwt-13 - https://forum.rvspace.org/t/arch-linux-image-for-visionfive-2/1459 ), I get about 216 MB/s read speeds. If I run the same command when running SF Debian 202306 on the same SSD I get about 173 MB/s - almost 50 MB/s slower.

[WillR81]

What was the CPU doing/speed at the time of the tests? The CPU speed, thus the governor active, has a tremendous impact on the NVME speed on the board.

https://forum.rvspace.org/t/what-kind-of-ssd-can-be-used/886/88

I saw similar differences in hdparm tests just by flipping the governor to wake the system up. I've tried this with both an Intel Optane 1600X and a Solidigm P44, and the results were similar. Both on the Debian 202306 build.

I haven't tried Arch on the board yet. What's the default governor with it?

[danboid]

THe VF2 was doing "nothing" except run GNOME, the GNOME terminal and hdparm.

[cwt]

I haven't tried Arch on the board yet. What's the default governor with it?

It is "ondemand". https://github.com/cwt/pkgbuild-linux-cwt-starfive-visionfive2/blob/521bfd7ecda5e6c3a39839e1b2d21add5232ca21/config#L6715

However, it is unfair to compare two different distros, more specifically two different kernels, as my kernel was built with clang instead of GCC, and also with heavily optimized flags for the JH7110 CPU.

[danboid]

Thanks for your input @cwt !

I don't think its unfair to compare the distros at all personally. There'd be nothing stopping StarFive from switching to clang to build their kernels, which sounds like a good idea from what you've just told us.