nvme performance

[ubuntu at howorth.org.uk]

noloader at gmail.com wrote:
> On Fri, Nov 18, 2022 at 8:34 AM Jerry Geis <jerry.geis at gmail.com>
> wrote:
> >
> > I have a new motherboard intel based Gigabyte Z790 Elite ZX.

And a quick check of the specs shows

 "4*PCIe 4.0 x4 M.2 Connectors"

> > I have a sabrent rocket 4T nvme that is supposed to get 7GB/s read.
> > When I run
> > dd if=/dev/zero of=tempfile bs=1m count=1024
> > I only get 4GB/s. Tested multiple times.
> >
> > What do I look at as why I'm not getting the higher read ?  
> 
> Are you on a PCIe x2 slot? x2 achieves 4 GB/s. Maybe you can try on an
> x4 slot? x4 can achieve 8 GB/s. And you also need a PCIe 4.0 compliant
> board.

So it seems unlikely that he would be using a x2 slot on a motherboard
that only has x4 connectors. Oh and a "1*SMD PCIe 5.0 x16 Slot with
Ultra Durable™ Armor" ??

> Also see
> https://www.crucial.com/support/articles-faq-ssd/pcie-speeds-limitations .
> 
> Jeff