Sign in with
Sign up | Sign in

Reply to this thread

Solved Forum question

Started by LaUs3r | | 4 answers
Mobo with 1xPCIe x16 for graphics & 1xPCIe x8 for 10GBit-NIC
Hey guys,

as the topic says, I'm looking for a motherboard that supports 1 x PCIe x16 for my graphics card and 1 x PCIe x8 for my new 10GBit-NIC (version 2.0 is enough). I know that there are plenty of mobos out there, that support 2 x PCIe but the catch is that if the second PCIe-slot is used the 1st x16-slot is downgraded to x8 or the 2nd is set to x4. For example the GA-Z97X-UD3H: afaik I can put my graphics card into the x16-slot, but as soon as I put the NIC into the second x16-slot, both are operated with x8.

Some facts about the NIC. It says "PCI Express 2.1 5 GT/s, x8" (Intel X540-T1). So I guess PCIe 2.0 is fine as well.

So, my questions:
1) do you know boards so that I can keep the REAL x16 for the 1st slot (graphics) and have x8 for the 2nd slot?

2) I currently have a Asrock Z68 Pro3 with 1 x PCIe 2.0 x16 slot. During games I'm absolutely fine with the current performance. So my idea is as follows: PCIe 2.0 x16 is approx. 8000MB/s. PCIe 3.0 x8 is about the same. So, if I go for a board that provides 2 x PCIe 3.0 that run x8 / x8 when both slots are used, I should get the same graphics performance like I have now and on top I have the perfect speed for the NIC right?

So I hope I was clear enough and appreciate your input already!
Cheers
  • By posting on this site, I confirm I am over 13 years of age and agree to abide by the site’s rules.

Best solution chosen by LaUs3r

a c 150 U Graphics card
a c 141 V Motherboard
October 17, 2014 11:06:49 AM

Unless you put in a M.2 drive, it'll not take the bandwidth away. And yes EX3 is a fine MoBo.
October 17, 2014 11:03:33 AM

Eximo said:
8x PCIe 3.0 is enough bandwidth for a single video card yes.

A lot of Z87 boards have the 16x/0x and 8x/8x PCIe slots, but usually also have an 8x PCIe 2.0 port.

Z97 is less likely on the top end since a lot of them have M.2 ports that take up 4x lanes.

I think X99 with a i7-5930k is about the only config that can do 16x and 8x at PCIe 3.0. (16x/8x/8x/8x)



Thx for the fast replies guys.
I already followed your suggestion to have a look at Z87 boards. But I didn't find a single one where the PCIe 2.0 x16 slot was not operated at x4 (1x PCIe 3.0 x16, 1x PCIe 2.0 x16 (x4))
But many thx for the hint with the M.2 ports. I didn't think of the fact that they use lanes as well :ange: 

So I guess I'll go for a ASRock Z97 Extreme3 with 2 x PCIe x16 (x8 / x8) and NO M.2-port.
With this choice I'm fine right?

a b U Graphics card
a c 96 V Motherboard
October 17, 2014 10:46:53 AM

8x PCIe 3.0 is enough bandwidth for a single video card yes.

A lot of Z87 boards have the 16x/0x and 8x/8x PCIe slots, but usually also have an 8x PCIe 2.0 port.

Z97 is less likely on the top end since a lot of them have M.2 ports that take up 4x lanes.

I think X99 with a i7-5930k is about the only config that can do 16x and 8x at PCIe 3.0. (16x/8x/8x/8x)

a c 150 U Graphics card
a c 141 V Motherboard
October 17, 2014 10:45:11 AM

1. Not technically possible with LGA1150 as CPU has only 16 lanes, but there are boards (like GA-Z87X-OC) which keep x16 on 1st PCIe while keeping x8 on second one.

2. And there's no performance difference in x8 or x16, even with very high end GPUs like GTX Titan:
http://www.pugetsystems.com/labs/articles/Impact-of-PCI...
^There's no difference in x8 or x16, the cards simply aren't fast enough.

See all answers