X99 STRIX Gaming - PCI x16/x16 SLI - x4 NVME Drive

[Gr33no]

Hi all,

Wondered if you could advise if I'm doing something boneheaded.

I've got a STRIX X99 GAMING mobo, Core i7 6850K (40 lanes), 2x GTX 1080 cards, 1x 1.2TB Intel 750 Series NVME (PCI-E) and a Sound Blaster Zx (PCI-E) audio card.

If I populate it with :-

GTX 1080 - PCIEX16/X8_1
N/A (covered up) - PCIEX1_1
Audio Card - PCIEX4_1
GTX 1080 - PCIEX16_2
N/A (covered up) - PCIEX1_2
750 Series - PCIEX8_3

My SSD will run @ Gen 3.0 x8 and perform properly in Windows.

This is the suggestion as per the ASUS manual for SLI

"Dual VGA/PCIe cards x16 x16 N/A"

But it also says

Triple VGA/PCIe cards x8 x16 x8


And that's what I'm being plagued with. My GPU POST shows the first PCI-E card running @ x8 with the second @ x16. GPU-z confirms this too.

If I swap the sound card and NVME drive - the drive performs at x2 speeds (so it runs at half speed, effectively) or maybe full if its a Gen 2.0 slot? - but the GPUs are read correctly - both @ x16.

Any ideas fine people? 🙂

Tom

[Legolas]

Maximum 40 lanes PCI for your setup. However, your setup is 16x+4x+16x+8x= 44 lanes total. 44 is above 40, so it will reduce one of your PCIE to 8x so 8x+4x+16x+8x=36. 36>40.
You need to take out of your cards or your GPU will slow down.

[Gr33no]

Legolas wrote:
Maximum 40 lanes PCI for your setup. However, your setup is 16x+4x+16x+8x= 44 lanes total. 44 is above 40, so it will reduce one of your PCIE to 8x so 8x+4x+16x+8x=36. 36>40.
You need to take out of your cards or your GPU will slow down.

The NVMe is (was) x4 though. This isn't being read correctly, that's where I believe the issue lay.

I'm fortunate to be in the hardware business and as this is my personal box, I moved the STRIX on and I've got a Deluxe II now - this works perfectly.

[Nate152]

Hi guys

By adding more pcie devices that would seem right for one of the gpu's to drop to x 8, I would have the dive where it's running full speed.