[SOLVED] 3080 and questions about Pcie lanes

Apr 6, 2022
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Hello.

OK, a few questions and any help is greatly appreciated.

My setup.

Msi Meg z390 godlike
Intel 9900k
Evga 3080 Ftw3 ultimate
32 GB of 3400 DDR 4
2 x Samsung Nvme 970 Pro m.2 pcie 3.0 ssd mounted on board, not using the expander card
Sound Blaster AE7 internal pcie sound card

OK, I bought a new GPU, the 3080. And a new cpu cooler, the noctua nh-d15 black. The cooler blocks the first pcie slot, the x16.

Now if course under idea circumstances, you would use the x16 slot. But since it's blocked I have to make some decisions.

If I am using 2 x nvme drives, and the sound card, does it knock down my effective pcie lanes to x8 for my gpu on the first slot anyways? Or worse, if I am using 2 nvme drives and the sound card does it knock me down to 4 lanes. I am using the small pcie 1x slot for the sound card. But if my effective lanes are 8x because of the nvme drives, than I can just use the godlike pcie_4 slot which is 8x by default. And should I just use the onboard sound if the sound card is using pcie lanes as well, and eliminate the ae7.

Or, will the first slot still work at X16, which from what I have seen it might not. But if it does, I can buy a vertical mounted pcie 3.0 riser and vertically mount the card, which will eliminate the AE7 anyhow.

Any advice would be appreciated. I have read up on a lot of it, but I want to be sure before I make any decisions.

Thanks in advance.
 
Solution
You will have a performance hit if you use a lower slot.

Noctua clearly states on their compatibility chart seen here: https://ncc.noctua.at/motherboards/model/MSI-MEG-Z390-GODLIKE-3004 that the D15 overhangs the primary PCIe x16 slot. This is exactly why they have the D15S which is offset back and away from the memory and graphics card. It has nearly the same performance as the D15 or there are a good many other high end coolers out there that may have better compatibility from brands like Thermalright, Deepcool, BeQuiet, Cryorig and Phanteks.

I'd recommend you return the cooler and get one that has better fitment.
You will have a performance hit if you use a lower slot.

Noctua clearly states on their compatibility chart seen here: https://ncc.noctua.at/motherboards/model/MSI-MEG-Z390-GODLIKE-3004 that the D15 overhangs the primary PCIe x16 slot. This is exactly why they have the D15S which is offset back and away from the memory and graphics card. It has nearly the same performance as the D15 or there are a good many other high end coolers out there that may have better compatibility from brands like Thermalright, Deepcool, BeQuiet, Cryorig and Phanteks.

I'd recommend you return the cooler and get one that has better fitment.
 
Solution
The first PCIe x16 slot typically shares no lanes unless there's another PCIe x16 slot. The other PCIe slots get their lanes from the chipset, but keep in mind that using those slots may disable other ports, like SATA ports. My memory's a bit hazy on whether or not one of the M.2 slots has its own set of lanes from a 9th gen Core processor or if it gets it from the chipset.

In any case, if you're worried about performance loss: https://www.techpowerup.com/review/nvidia-geforce-rtx-3080-pci-express-scaling/27.html