General Discussions

[amolpandit]

I have a X570 Taichi Razer Edition. I have a Ryzen 7 5700x3D, 3080ti along with a WD SN850X 1tb on M2_1 slot ie. Closest to the CPU and a WD SN580 2tb on M2_2 slot. The M2_1 slot I believe uses PCI-E lanes from CPU and M2_2 slot uses PCI-E lanes from chipset. But inspite of what the manual claims the M2_1 slot is running my SSD @ Gen4 x2 lanes instead of x4. I contacted ASRock but all I got is reseat the CPU. Which I did but nothing changed. Now I don't know what to do. So trying my luck on AMD forum. 

[johnnyenglish]

I  can't say I've read carefully the manual but M.2 slot 1 and 2 come from CPU so you are sharing lanes. Try it on slot 3 or 4 maybe.

Good luck 

[amolpandit]

I have a WD Blue SN580 On the M2_2 slot which runs at Gen4 x4. So that's fine. I just updated BIOS to latest version but that didn't fix the issue. Managed to get a Ryzen 5 3600 which has PCI-E Gen4 support, will try to put that in the system and try. If not then board is the issue. This has been driving me crazy. 

[elstaci]

According to ASRock specs on your Motherboard your Ryzen 7 5700x3d (VEMEER) should both run at Gen4x4 in M.2 slots 1 & 2:https://www.asrock.com/mb/AMD/X570%20Taichi%20Razer%20Edition/Specification.asp#Specification

According to Monkey-CPU processor site the 5700x3D is a Vemeer Gen 3 processor with PCIe bandwidth as follows: https://www.cpu-monkey.com/en/cpu-amd_ryzen_7_5700x3d

NOTE: All of AMD 5000 series has the same PCIe Bandwidth limitation of 39.4Gb/s which is less then GEN 4x4 Bandwidth of 64gb/s.

NOTE: Found out my Matisse Ryzen 7 3700x has the same maximum PCIe bandwidth as the Vermeer Ryzen 7 5700x3D.

[FunkZ]

You've run out of available lanes.

As @elstaci points out the CPU has 20x usable PCIe 4.0 lanes and both the M2_1 and M2_2 sockets use CPU lanes. Assuming you've got a graphics card taking 16x you're out of lanes.

As @johnnyenglish suggests, move the M2_2 drive to a socket run off the chipset.

[amolpandit]

I got a reply from ASRock where they tested the same config. And it runs Gen 4x4.

Secondly

Ryzenz have 24 Native PCIE lanes. But only 20 are available since 4 are for chipset downlink. 16 for GPU and 4 for the storage. So it should not run out of PCI-E lanes. I will try to troubleshoot this, but worst case I will RMA the board and ask for live demo at service center before accepting replacement. 

[FunkZ]

So ASRock is stating that two NVMe drives can share four total PCIe lanes but both get 4x bandwidth?!?

That's like stating that you can run dual 16x graphics cards in two slots and get 32x lanes of total bandwidth. No, when you double the cards each only gets half the bandwidth. (2x8)