Asus x570pro 2nd m.2 slot

Wagz3 · January 12, 2022

I filled up m.2 1 next to chipset. This is right where my 3070 is. There is an lower m.2 gen 2 nvme slot 2nd slot that acording to manual will run at x4 speeds. I'm getting conflicting answers from asus. Some says it will run at gen 4x4. Called on different issue on whether I needed a standoff for 2nd slot since I don't have one and asked again about 2nd m.2 speed sharing lanes. He mentioned since I have an external graphics card it will only run at x1 speed, slow as hell. I originally bought 970 evo plus, but found 980 pro for 40$ more so I said screw it, take advantage of gen 4 since 2nd m.2 will be slower anyhow. I can't get a real answer on this. Asus X570 pro. 3070, 5600x cpu. If it's x1 I could have bought any nvme with speeds that low. Also will it take any lanes away from gpu. I'm a novice here. lost. probably wasted money on higher end nvme cause I know the load times are about 1 second difference. Thanks for any help.

tim0901 · January 12, 2022

To find the answer to this you will need to follow the physical PCB traces that lead from your top NVMe slot.

If they head to the CPU - great news you should be fine. This slot is managed by the CPU and since you get 24 PCIe lanes with Zen 3, it will use four of those. Four more of these lanes go to your chipset and the other 16 lanes will go to your 3070.

If they head to the chipset, not so good news. Both NVMe drives will be sharing the 4 lane uplink between the chipset and the CPU alongside your USB ports, SATA ports, networking etc. But unless you're hitting both drives at the same time, or are transferring from high-speed USB storage, I doubt you'll notice the difference.

My guess is that it's the first scenario, but without physically looking at the board I can't be certain as the manual doesn't specify.

tim0901 · January 12, 2022

Okay I found the answer in the manual, it's just hidden.

As you can see, it specifies that M.2_1 is connected through the processor, while M.2_2 is connected through the X570 chipset. As such, you should be able to get the full performance out of both drives.