M.2 PCIe card. 40 lane CPU question

[FML1990]

How does the M.2 cards (such as the intel 750) effect PCIe lanes.

Say I have an X99 board, and a cpu with 40 lanes.

The manual only says SLI and crossfire configurations.

If I have 2 cards, and then this M.2

Would the two GPUs still run at 16x
Or would all GPUs act as if the M.2 was a GPU. Thus dropping the speed to 16x, 8x, and 4x (even though a third GPU would be 8x, the max speed of this is 4x)

Or would they run at 16x 16x 4x

 

[FredFlint]

The Intel 750 uses 4 lanes so the system has 36 left for the GPU's and other PCI-e slots. I think it would run @ 16x, 16x and 4x so you could have 2 16x GPU's and 2 4x SSD's depending on the mainboard.

 

[HoneyBadger]

The Intel 750 uses 4 lanes so the system has 36 left for the GPU's and other PCI-e slots. I think it would run @ 16x, 16x and 4x so you could have 2 16x GPU's and 2 4x SSD's depending on the mainboard.

Correct.

Assuming your X99 board has 2 or more physical 16x lanes, then it would be:

CPU= 40 lanes avaliable

Graphics card 1: Full 16x lanes
Graphics card 2: Full 16x lanes
M.2: x4 Lanes

Total used: 36 lanes, 4 left.

If you tell us your X99 motherboard, I'll let you know for sure if it has >2 16x Lanes, but being X99 I'd be VERY surprised if it didn't.

 

[demonix]

It actually depends on what PCIe slot the M.2 slot is bound to for PCIe M.2 drives, so if it's bound to one of the 16x slots then it will reduce that slot down to most likely an 8x slot.

All of this should be shown in the specifications on the motherboard manufacturers website and the manual.

 

[HoneyBadger]

It actually depends on what PCIe slot the M.2 slot is bound to for PCIe M.2 drives, so if it's bound to one of the 16x slots then it will reduce that slot down to most likely an 8x slot.

Not on X99.

 

[demonix]

Not on X99.

https://www.overclockers.co.uk/asus-x99-e-intel-x99-socket-2011-ddr4-atx-motherboard-mb-68a-as.html

*The M.2 socket shares bandwidth with PCIe X16_3

You was saying..... (and that isn't the only X99 board that has shared PCIe bandwidth).

 

[HoneyBadger]

I stand corrected.