ASUS Z790-F Strix M.2_1 Lose Performance in GPU

[warriorunited]

Hello everyone.

I've grabbed a ASUS Z790-F Strix for a good price and going to replace mine B660-F Strix with it.

I was reading some stuff about the motherboard, and is it true that if i place any SSD in M.2_1 slot, i lose PCI5.0 performance? I'm going to put there a Samsung 970 Evo Plus 1TB, wich is not even Gen 4 SSD...

Thanks!

 

[Marcus L]

A gen 3 drive won't run at pcie5 so you'll lose no performance

 

[Dan.G]

I think it's dependant on the chipset. M.2_1 is linked to the CPU, so if it supports x20 lanes, x4 will be allocated to the M.2_1 and x16 to the GPU. Shouldn't be a problem.
Intel® Z790 Chipset
Supported Processor PCI Express Port Configurations: 1x16+1x4 or 2x8+1x4.
Should be fine.
Regarding PCI-Ex 5.0 performance... well, there aren't any GPUs that can take advantage of that, so no way to be sure. But, even if it would back down to 4.0 speeds (for some reason), it should be more than enough. RTX 4090 runs fine on PCI-Ex 4.0 x16.

 

[warriorunited]

Still weird that I've found informations regarding issues with this.. Maybe they changed it with a bios update? Because people say it was on mobo specs, and I can't see that information anywhere, either in manual.

PSA: STRIX Z790-E M.2_1 forces PCIEX16(G5) to run x8 only

My STRIX Z790-E arrived today, and while I love the motherboard so far I clearly did not read the fine print: https://rog.asus.com/us/motherboards/rog-strix/rog-strix-z790-e-gaming-wifi-model/spec/ ** When M.2_1 is occupied with SSD device, PCIEX16(G5) will run x8 only. This strikes me as...

rog-forum.asus.com

 

[pressing on]

Still weird that I've found informations regarding issues with this.. Maybe they changed it with a bios update? Because people say it was on mobo specs, and I can't see that information anywhere, either in manual.

PSA: STRIX Z790-E M.2_1 forces PCIEX16(G5) to run x8 only

My STRIX Z790-E arrived today, and while I love the motherboard so far I clearly did not read the fine print: https://rog.asus.com/us/motherboards/rog-strix/rog-strix-z790-e-gaming-wifi-model/spec/ ** When M.2_1 is occupied with SSD device, PCIEX16(G5) will run x8 only. This strikes me as...

rog-forum.asus.com

The link refers to the E and your have the F. One of the differences is that your M2_1 is PCIe 4.0 x 4; with the E it is PCIe 5.0 x 4. So this issue does not affect your motherboard.

It is correct that if you fill the E's M2_1 slot with a PCIe 5.0 drive the graphics card slot drops to x 8. But as I understand it, this is PCIe 5.0 x 8 which is the same as PCIe 4.0 x 16. So in the absence of any PCIe 5.0 graphics cards this has no practical effect for the owners of E boards.