Re: NVMe drives - what's the story?

On Tue, Jan 12, 2021 at 9:28 PM P=C3=B3l Ua Lao=C3=ADnech=C3=A1in <linehanp=
@tcd.ie> wrote:
>
> Hvala moj prijatelj i kako si?
>
> (wrote that from memory - just had to check the spelling of "prijatelj")

\o/ Go raibh maith agat! T=C3=A1 m=C3=A9 go maith.

[I had to use Translate for this, even 7yr later. Maybe I should
double down on Duolingo lessons...]

> > I got a relatively-cheap PCI NVMe with M2 interface, plus an adapter
> > from M2 to PCI, and the games are loading very, very quickly. Looks
> > like the CPU is now my bottleneck for games.
>
> What's the difference between PCIe, M2 and NVMe with an M2 interface?
>
> AIUI, you can have M2 SATA and M2 PCIe?

What I'll say might be silly, as it comes solely out of what I
received in my order and a bit of talking with friends before my
purchase -- someone please correct me.

1) PCI Express is the "(usually) big slot" on your motherboard. Think
"this is where the wifi card goes" or "this is where the GPU goes".
2) M2 interface is really, really tiny. Think "when I open a laptop,
there's some space to plug something in".
3) Even if it has the M2 interface, the drive can still talk only
SATA. The adapter from M2 slot to the "big" PCI Express slot which I
bought explicitly said that the drive must *not* be SATA-only -- that
it only adapts M2 interface drives which talk PCI Express 3.0.

I am not fully sure what M2 exactly is -- I simply never looked up in
sufficient detail. Similarly, I don't know exactly in what physical
sizes PCI Express slots can come in.

> What then is "normal" PCIe?

I assume there are storage devices which can be plugged directly into
the big PCI Express interface, sized for desktop network cards, GPUs
etc?

> I see various things offered on Amazon
>
> (going to get a friend who lives in the gigantic lunatic asylum known
> as the USA to buy a machine for me - when he ever comes back - his
> mother is in a home and he won't be able to visit even if he does come
> now...)
>
> and I'd like to know what I'm getting...

I bought this 1TB drive:
  https://www.amazon.co.uk/gp/product/B087QRVVVH

When everything arrived, I was really happy that I bought this adapter
at the same time:
  https://www.amazon.co.uk/gp/product/B075TF6HFM

I was really happy given that this is when I realized how tiny M2
interface really is. You see the big PCI Express interface that you
get to plug into your motherboard? Compare it to the tiny slot that
the arrow points to.

>
>
> > If you suspect disk access is your bottleneck,
>
> I'm a database nerd, so faster disk access is the holy grail...
> graphics and CPU... meh...
>
> Some of the machines have a SATA 2.5' drive bay and an M2 slot - I got
> one of these (spinning rust HDD and empty M2 - put an SSD in 2.5' bay
> and an M2 SATA drive (no point in getting PCIe for a SATA compatible
> slot) and it hums - but I'd like to try the "fully monty" of "pure"
> PCIe NVMe...

Given how cheapo the adapter is, and given that it works fine on
Windows for me, I'd go for it.

I can't remember if I tried to make it work on my Debian installation.
I certainly left some unallocated space for a partition, but I'd need
to reboot to see if the device is properly recognized. I *think* the
UEFI sees it, but I'm not 100% sure about that either.

(It's not my boot drive at this time.)

>
>
> Videmo se,
>
>
> P=C3=B3l...

o/

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