Question on lanes and PCIE5 vs PCIE4

[Mallers]

Hello,

Im looking at motherboards, and getting into learning about lanes. Lovely!

I looked at the MEG Z790 Ace first, and it says that there is a PCIE 1 slot at 5.0x16, PCIE 2 at 5.0x8 and PCIE 3 at 4.0x4.

So firstly, my assumption is one would want the GPU plugged into PCIE 1 which has greater bandwidth?

Next, which is the meat of my question, the M.2 SSD slots. Only one, M2_4 is a PCIE 5 slot, all others are PCIE 4. But if I use this slot, it reduces the PCIE 1 GPU slot from 5.0x16 to 5.0x8

Im gradually getting my head round lanes via YouTube! But am I right in thinking that on this board, you CANNOT have both a GPU and an SSD both using PCIE 5? IE if you have one, it locks out the other?

Is this the case with all the Intel boards, and if im gaming and want to run eg Starfield or Warhammer 3, would I really notice much difference between an SSD on PCIE 4.0x4 vs running at PCIE 5.0x4 and/or a GPU running at 5.0x16 vs 5.0x8?



Regards,

Mallers

 

[Rroff]

Right now you'll notice zero difference for gaming between a fast PCI-e 4.0 and 5.0 NVME. Direct Storage might change that eventually but better IMO to have the GPU having full bandwidth available to it - we'll probably see PCI-e 5.0 GPUs before games take advantage of PCI-e 5.0 storage in any meaningful way.

 

[Tetras]

But am I right in thinking that on this board, you CANNOT have both a GPU and an SSD both using PCIE 5? IE if you have one, it locks out the other?

Is this the case with all the Intel boards

Question 1:

The graphics card and SSD may both be PCI-E 5.0, but the consequences depend on the motherboard. Usually it just means that the graphics card is limited to 8 lanes.

But, with the ACE, it has two PCI-E 5.0 slots and you can't use the second slot with the PCI-E 5.0 M.2 slot (i.e. if you use one, the other one is disabled).

Question 2:

Yes, it is a CPU limitation since they only have 16 PCI-E 5.0 lanes. AM5/AMD 7000 doesn't have this problem.

 

[JollyJamma]

Hello,

Im looking at motherboards, and getting into learning about lanes. Lovely!

I looked at the MEG Z790 Ace first, and it says that there is a PCIE 1 slot at 5.0x16, PCIE 2 at 5.0x8 and PCIE 3 at 4.0x4.

So firstly, my assumption is one would want the GPU plugged into PCIE 1 which has greater bandwidth?

Next, which is the meat of my question, the M.2 SSD slots. Only one, M2_4 is a PCIE 5 slot, all others are PCIE 4. But if I use this slot, it reduces the PCIE 1 GPU slot from 5.0x16 to 5.0x8

Im gradually getting my head round lanes via YouTube! But am I right in thinking that on this board, you CANNOT have both a GPU and an SSD both using PCIE 5? IE if you have one, it locks out the other?

Is this the case with all the Intel boards, and if im gaming and want to run eg Starfield or Warhammer 3, would I really notice much difference between an SSD on PCIE 4.0x4 vs running at PCIE 5.0x4 and/or a GPU running at 5.0x16 vs 5.0x8?



Regards,

Mallers

You won’t notice a difference between 5.0 or 4.0.

Just make sure your GPU runs in a slot with all 16x lanes active.