Re: Call for testers with NVMe

Reply: Ruslan Zalata : "Call for testers with NVMe"
In reply to: Ruslan Zalata : "Call for testers with NVMe"
Go to: [ bottom of page ] [ top of archives ] [ this month ]

From: Abdelkader Boudih <seuros_at_freebsd.org>
Date: Sat, 19 Sep 2026 20:31:58 UTC

`nvmecontrol perftest -n 4 -o read -s 4096 -t 30 nvme0ns1` << here, you are reading 4K.

`nvmecontrol perftest -n 4 -o read -s 81920 -t 30 nvme0ns1` << and here, you are using only 4 threads to read 80K.

The numbers are correct.

max theoretical throughput is: 8GT/s*4*(128/130)/8 = 3.94 GB/s.

That is also correct, but that is the top speed of the bus not the drive.

Your HP EX900+ is a budget drive. The controller was never built to reach that speed. Having access to the Autobahn in Germany doesn’t suddenly make your car go 300 km/h. :)

Try:

nvmecontrol perftest -n 32 -o read -s 4096 -t 30 nvme0ns1 
nvmecontrol perftest -n 32 -o read -s 131072 -t 30 nvme0ns1

and maybe try with -n 64.

I would be interested in seeing how the IOPS and bandwidth scale with the number of outstanding requests in those drives.

Thanks
Abdelkader