I have a 44 Lane CPU and two Titan RTX in SLI on my motherboard that would be 32 PCIE lanes used and I also got a Intel 900p U.2 which would make it a total of 36 PCIE lanes consumed and I was wondering where I need to place my M.2 drives so everything runs at maximum speed and from the CPU.
There is two M.2 slots on the board and another 2 on the Dimm.2 slot but according to the manual M.2_2 shares the bandwidth with the U.2 slot and M.2_1 runs from the PCH ? and shares bandwidth with PCIE 3.0 x4 according to some reviews online, that means Dimm.2 is my only option but where does Dimm.2 get lanes from ? apparently you cant run U.2 and Dimm.2 at the same time.
I also have a question about PCIE 3.0 x4 slot and I was wondering how im supposed to put my sound card inside this slot since my bottom Titan blocks the slot since the IO is 2 slot while the card itself is 1 slot now with the waterblock, can I cut the plate and remove the bottom display port ? or would that cause the card to stop working ? I really want to use that PCIE 3.0 x4 slot and I cant figure out how to mount it, I did try the last PCIE 3.0 x16 slot and it turns the GPUs into 8x 8x mode instead of 16x 16x and this reduce my performance a lot. I have only seen 16x Riser cards and maybe I can cut this into 4x ? or would that cause signal to worsen ?
Last resort I see is to buy that new Rampage Vi Extreme Encore motherboard since that one have the PCIE 3.0 X4 slot in between the two GPUs so that would work but ditching out 1000 dollars for a brand new motherboard with minimal upgrades over the omega and also losing the U.2 really would suck
When I got the board I tried to find the lane allocations via HWInfo, you can find my result here.
For the M.2 ports it looks like this...
M.2 Slots (12 CPU lanes in total / 4 via PCH)
M2_1 Onboard (between PCIEX16_2 and PCIEX16_3) -> PCI Express 3.0 4x via PCH
M2_2 Onboard (between PCIEX16_1 and PCIEX16_2) -> PCI Express 3.0 4x via CPU
DIMM.2_1 Module -> PCI Express 3.0 4x via CPU
DIMM.2_2 Module -> PCI Express 3.0 4x via CPU
Have no U.2 to check how those are connected, but according to the manual it shares the lanes with M.2_2 connected to the CPU.
PS Before you cut your Titan RTX, give it to me. I could use this beast for GPU rendering 🙂 There are PCIe 4x riser cables on the market! So I would go this way or use another sound card (USB or just onboard).
Thanks a lot for the info, I guess I’m safe then with two Titan RTX, intel 900p U.2 and two 970 Evo plus on Dimm.2 that would be total of 44 Pcie.
Since M.2_1 goes to PCH will that turn of the PCIE 4x slot ? If that M.2 slot is used or would it just be running lower bandwidth since I will have a sound card there ? Since I believe M.2_1 is routed to PCIE x4 that runs from the PCH.
Indeed I also did see that there is 4x PCIE riser cables just very ugly looking ones 😕 guess that’s better than cutting into a 3000$ card lol x2 also.
Everything connected to the PCH will be able to run at the same time, but shares the DMI 3.0 connection to the CPU (which equals PCIe 4x speeds, as far as I know). Your sound card wont use much bandwidth, so I wouldn't expect any noticeable impact on the NVMe performance, at least not in real life, maybe in benchmarks.