Soundcard in 16x slot?

[eddiew]

Hey peeps,

I'm eyeing up a Gigabyte mATX board for my next build. I only have/want a single GPU, but I also have a Soundblaster Z, which is a 1x PCI-E device. These will be the only things in the PCI-E slots, so one will be unused.

1) can I plug the Soundblaster into the lower 16x slot? (this will give better airflow to the GPU)
2) will doing so cause the top GPU slot to drop to 8x?
3) does adding an M.2 SSD at a later date change anything, given that this will occupy another PCI-E lane?

(Also sly 4th question, is there any reason to believe the mATX version of this board is worse than its full ATX counterpart if you don't need the extra slots? I would like to shrink my rig, but not at the cost of knackering performance or overclocking potential.)

Thanks in advance!

 

[EsaT]

If PCI-e card fits physically (without violence) it works.
PCI-e bus controller and card negotiate amount of used lanes, basing on how many lanes are available/wired to slot and how many lanes card can use.

And it seems to be x4 slot likely using lanes from chipset.
If it shared lanes with main PCI-e x16 slot it would be electrically x8 slot.

M.2 SSD slot might share lanes with it, but with SB Z needing only one lane it doesn't make difference if that slot drops to max x2 mode.
User manual should tell how that works.
I don't have time now to read it.

 

[eddiew]

Thanks @EsaT , I hadn't noticed the x4 further down the page. That's probably good news

 

[mattyfez]

Yeh use the smaller x4 slot if possible, but if it's a pci-e card it should theoretically be fine in one of the main faster ones, but it won't be of any benefit.

 

[EsaT]

According to manual that x4 wired slot is PCI-e v2.0 meaning it doesn't affect main x16 slot.

As another good thing it leaves good "breathing space" between sound card and graphics card so that GPU cooler can get cooling air and sound card isn't heated so much.

 

[eddiew]

Exactly my thoughts @EsaT , thanks for the jargon translation (I'm a little out of date with regards to hardware these days). Good to know that it won't interfere with the GPU by means physical or electrical

...now that I think about it, I thought B350 wasn't for x-fire anyway, so yeah, makes sense that it is NOT another x16/x8 slot. Now I feel like I want to learn what uses a full length slot but is x4 electrically...

 

[EsaT]

Even graphics cards work in x4 mode.
https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_PCI_Express_Scaling/24.html

Also hardware RAID controllers are usually x4/x8 cards.
While existing as design don't know if there's actually x8 physical slots in use.

 

[eddiew]

Ahh, good to know, cheers

 

[Smffy]

You can also set the speed manually in the BIOS on most boards so set to x4 if required. Depends which CPU and chipset you're talking about anyway but doing that or using a x4 slot will keep the GPU at x16.

Not that you'd notice the performance drop in normal applications at x8

 

[eddiew]

You can also set the speed manually in the BIOS on most boards so set to x4 if required. Depends which CPU and chipset you're talking about anyway but doing that or using a x4 slot will keep the GPU at x16.

Did not know that, thank you And yeah, it does look like 8x-16x is a very small increase that I would probably not spot unless I went looking for it ^^;

 

[Smffy]

Did not know that, thank you And yeah, it does look like 8x-16x is a very small increase that I would probably not spot unless I went looking for it ^^;

No probs, only know it's possible on Asus boards to be fair but assume most would allow it. Good luck!