X99 moptherboard to support SLI and NVMe?

[Crash55]

For my new build I will be using:
Core i7-6850k
2x EVGA GTX 1080 FTW
an NVMe drive - preferred drive is 1.2TB Intel 750, could use Samsung 950

Since the CPU supports 40 lanes I want to have the GPU's at x16 and the drive at x4. I am currently looking at three motherboards and was hoping someone can tell me if the will work or not. After reading the ROG forums I am concerned that I could wind up slowing down the primary graphics slot. I know there is little difference between x16 and x8 but if I am spending this much money I want everything right.

Asus Rampage V Edition 10
The GPUs would go in slots 1 and 3. That leaves slot 4, M.2 and U.2 available.
However I saw on the Asus ROG boards that using slot 4 causes issues and that if you use the U.2 slot it turns on the M.2 and reduces slot 1 to x8.
So it looks like only an M2. drive would work with this board?

EVGA X99 FTW K
The GPUs would go in slots 1 and 5. That leaves slot 6 and M.2 available.
So the Intel 750 would have to go in slot 6 or a Samsung in M.2.
Does anyone have any experience doing this?

MSI X99AGodlike Gaming Carbon
GPUs would go in Slot 1 and 4. That leaves slot 5 and M.2 available
The Intel 750 could go in slot 5 or use the U.2 adapter in the M.2 slot or Samsung 950 in M.2 slot
Does anyone have any experience doing this?

 

[Pr3d4t0r]

dont bother with x16, just get the mobo you want with features you want it to have.

unless you're going to run insane gpu rendering on those cards then you will not see a single fps difference between x8 pcie2 and x16 pcie3.0

more people have done research on this, quick google will do.

 

[Crash55]

I know there isn't much difference but why take any hit if I don't have to? I am not fixed on any of the boards though the ASUS and MSI look better than the EVGA.

As an engineer it will bother me knowing that things are not working as good as they should.

 

[Pr3d4t0r]

https://www.pugetsystems.com/labs/a...Speed-on-Gaming-Performance-518/#1080pResults

what if i told you that pcie2 x8 has better performance than pcie3 x16

and honestly, we're nowhere near a level where we're close to saturation even original pcie1 spec bandwidth. unless you're using it for proper gpu rendering purposes where you may see a difference when you throughput actually can make a difference.

oh and don't buy into the mobo manufacturers meme of needed a new x99 board to run the haswell-e refresh cpu's

I prefer msi design myself but i am black and red biased

 

[Crash55]

I would say the tests show that either the cards or the software can't take advantage of the higher bandwidth and what we are seeing are run to run variations. If you take a larger sample set I bet they average to the same.

I am sure the older X99 boards would work fine provided the BIOS was updated for Broadwell-E. However the newer boards are mostly refreshes so they should have fixed the bugs in the old ones right?

I know this fixation with x16 is probably meaningless but I normally keep a PC 3 - 5 years so there will probably be a second set of video cards at some point and it may matter then.

 

[chris84]

I just installed an Asus Strix x99 Gaming with a 6850k, single GTX 1080, 16GB dominator RAM and Samsung SM951 M2 SSD.

System is great. Couldn't justify dual GTX 1080 at the minute but it leaves room to expand in future. Can game at 4k 60fps on Acer B326HK without a problem or 1440p 100fps+ on my new Asus PG279Q.

This is what it looks like in the case, hope it helps.

Chris