ASUS Rampage V Extreme ??

[Dangz]

ok I have the ASUS Rampage V Extreme and I have two 980 ti s in SLI the first one is running at 16x native so my issue here is that the second one is only running at 8x native I don't understand why?? first PCIE_X16_1 AND SECOD 980 TI is on PCIE_16/x8_3 I cant run my second 980 TI in 16x native only at 8x native why? I tried couple option in the bios but no change

 

[joex444]

Do you have an i7-5820K? Those CPUs only have 28 PCIe lanes, so you'll get x16/x8 since that's 24 lanes but x16/x16 is 32 lanes.

For x16/x16 you need a 40 lane CPU, like the i7-5930K or i7-5960X. I mean, those are literally the only other two consumer level CPUs for that socket, but there are plenty of Xeon chips that also run in that board that would offer you 40 lanes.

 

[Kryptkeeper]

Also not to worry, unless you running a dual gpu in x8 which you aren't you wouldnt see any performance difference between using x16/x16, x16/x8 or x8/x8

 

[riccardi50]

It is either one or the other issue:

You don't have a cpu that gives you enough PCIe lanes. What cpu are you using? In order to run 16x and 16x you need a 5930k or higher.

The second reason is that you have the 2nd card in the wrong slot. Check your mobo manual which one you need to put it in to run 16x16x SLI.

But regardless, you aren't going to see a bottleneck or a slow down in performance if you run 16x, 8x. You just won't. Look it up on Youtube, plenty of videos showing the performance of 16x16x vs 16x8x.

Hope that helps.