Re: Read/write slow on nvme drive - Supermicro X10DRL-CT

[Warner Losh <imp%bsdimp.com@localhost>]

On Mon, Aug 8, 2016 at 10:42 AM, Derrick Lobo <derrick.lobo%givex.com@localhost> wrote:
> This is surely NVME hardware both motherboard and drive support nvme.
> Using ubuntu liveboot disk utility I was able to gt 3.8gb read and write
> speed..


FreeBSD is able to get that from the NVMe drives we buy at work for our OCA
boxes (the drives we have top out at 3.9GB/s). However, if you are doing
benchmarks, you usually need a high thread count and a deep queue depth
to get close to those numbers. I have to use the fio benchmarking utility to
see such throughput outside of an OCA streaming video (which does everything
via sendfile). Through userland interaction I see a lot less through UFS, but I
haven't spent a lot of time on benchmarking.

You might see if you can get better numbers that way. Read will be no problem
to test, but only test write if you don't need what's on the NVMe drive :)

We also had to make a few tweaks to the Intel driver when we started testing
to avoid excessive queueing of results that queued results to get the last 10%
or so of performance. The only way we were able to tune was in a live system.

Good luck,

Warner

P.S. We've also tested other drives that top out at between 2.9-3.2GB/s. Not all
NVMe drives are created equal.