Can I Run 16x PCIe in Second Slot on MSI Z790?

[FRZ]

I bought an MSI MEG Z790 Ace, but because of my EK Waterblock, the GPU will only fit properly in the second alot. I was under the impression the Z790 can choose which PCIe slot runs at 16x but I can't figure out the proper setting in the BIOS.

Any ideas?

I have an M.2 drive in the first M.2 slot. Is that preventing me from allocating all 16x lanes to the GPU?

 

[toast0]

I bought an MSI MEG Z790 Ace, but because of my EK Waterblock, the GPU will only fit properly in the second alot. I was under the impression the Z790 can choose which PCIe slot runs at 16x but I can't figure out the proper setting in the BIOS.

Any ideas?

I have an M.2 drive in the first M.2 slot. Is that preventing me from allocating all 16x lanes to the GPU?

Spec page says:

PCI_E1 Gen PCIe 5.0 supports up to x16 (From CPU)
PCI_E2 Gen PCIe 5.0 supports up to x8 (From CPU)
PCI_E3 Gen PCIe 4.0 supports up to x4 (From Chipset)

*PCI_E1 slot will run at x8 speed when installing device in the PCI_E2 slot or M2_4 slot.
**M2_4 slot will be unavailable when installing device in the PCI_E2 slot.

So I'm thinking you'll get x8 to the cpu if you use the slot, and the m2_4 slot will not work. PCIe lanes aren't super flexible these days, so it is what it is.

 

[rhkcommander959]

Which gpu you got? Pcie 4.0 x8 is plenty of bandwidth still

 

[FRZ]

Which gpu you got? Pcie 4.0 x8 is plenty of bandwidth still

I have a 4090. I know the performance difference is negligible, but just kind of annoyed you can switch the lanes on the evga Z790 but not the MSI