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

[coypu%SDF.ORG@localhost]

On Wed, Aug 03, 2016 at 03:13:43PM -0400, Derrick Lobo wrote:
> I have a Supermicro nmve supported hardware X10DRL-CT with a SSD sasa
> drive and an intel nvme pcie drive.. both drives are 2tb and I have used
> gpt with the latest 7.99 daily build from today
> 
> Using netbsd using dd if=/dev/device of=/dev/null bs=16k
> Sata SSD : 33967620096 bytes transferred in 1899.583 sec(17881619
> bytes/sec)
> pcie SSD : 308527169536 bytes transferred in 2384.793 sec(129372725
> bytes/sec)
> 
> Using ubuntu live boot disk with diskutility I get
> Sata SSD :  504MB/sec
> pcie SSD : 3100MB/sec
> 
> So im wondering if theres any tweak/config  on netbsd that is needed to
> get higher speed on the pcie .. copying a 200mb files take a minute on the
> sata drive while it takes 6 minutes on the pcie.. so its 5 times slow
> rather than being faster
> 
> Derrick Lobo
> 

One thing worth noting is that GNU dd "lies" so to speak. it'll
terminate before it's actually done writing. this is evident by trying
to run 'sync' after.

it would be best if you ran a benchmark which eliminates some of the
oddities, like bonnie++. it's in netbsd under
pkgsrc/benchmarks/bonnie++, and I'm sure there's a package for your
favourite linux distro.

(it'll also ask to write more than your given RAM to try to eliminate
cache behaviour differences, etc.)