[RESPONDED] Framework 13 USB 4 PCIe Lanes

[Matt_Hartley]

@ryanpetris

I was trying to figure out why one of my eGPUs worked with my Framework 13 Intel i7-1370p but doesn’t work with my new Framework 13 AMD 7840U, and noticed that I’m only getting an x1 link on AMD while I’m getting and x4 link on Intel. This is what I’m seeing in dmesg:

[  134.193344] pci 0000:62:00.0: 2.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x1 link at 0000:00:04.1 (capable of 31.504 Gb/s with 8.0 GT/s PCIe x4 link)

lspci for the thunderbolt tunnel also shows an x1 link:

00:04.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 19h USB4/Thunderbolt PCIe tunnel (prog-if 00 [Normal decode])
        Subsystem: Advanced Micro Devices, Inc. [AMD] Family 19h USB4/Thunderbolt PCIe tunnel
                ...
                LnkSta: Speed 2.5GT/s, Width x1
                        TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt-
                ...

Are the USB ports on the AMD Framework 13’s only 1-lane ports instead of 4 like on the Intels? If they are in fact 4-lane, is there some trick to make them run at full speed?

Note that this happens with a few Thunderbolt devices I have, not just with an eGPU.

Edit: I’m running an updated Arch install with the latest kernel:

Linux grazier 6.6.1-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 08 Nov 2023 16:05:38 +0000 x86_64 GNU/Linux

We don’t test eGPUs per se, however can you tell me which port you are connecting to?