B550M Hardware support for dual pci-e on wifi m.2
Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=26912
Printed Date: 26 Jul 2025 at 3:44pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: B550M Hardware support for dual pci-e on wifi m.2
Posted By: duindain
Subject: B550M Hardware support for dual pci-e on wifi m.2
Date Posted: 24 Oct 2023 at 5:56am
Hi
I'm trying to use the Wifi M.2 slot with a google coral dual tpu, it seems to work but only with one tpu atm
Does this m.2 slot support dual pcie lanes?
According to the information from the google coral doco
"the M.2 Specification (section 5.1.2) declares E-key sockets provide two instances of PCIe x1, most manufacturers provide only one"
This has been asked already by someone else but in the wrong section of the forums
https://forum.asrock.com/forum_posts.asp?TID=26194&PID=106721&title=asrock-b550m-steel-legend-m-2-socket-key-e-lanes#106721" rel="nofollow - https://forum.asrock.com/forum_posts.asp?TID=26194&PID=106721&title=asrock-b550m-steel-legend-m-2-socket-key-e-lanes#106721
Full description for Google Coral is here: https://coral.ai/products/m2-accelerator-dual-edgetpu/" rel="nofollow - https://coral.ai/products/m2-accelerator-dual-edgetpu/
Cheers
|
Replies:
Posted By: eccential
Date Posted: 24 Oct 2023 at 6:34pm
I don't get why they chose to make it E-key, since everyone should know most implementation of A/E slots only support a single lane of PCIe. Even adapters that let you put WiFi modules (A/E) onto NVMe slots (M) I see on Amazon say they only route one lane.
They should've made it for M-key, in my opinion. Then again, I wonder if it would work as 2 units even on a typical M-key slot. If it's truly 2 independent units, wouldn't it require PCIe bifurcation support?
If so, perhaps that explains why they picked E-key. It's to be a specialty equipment from the get go.
On an unrelated note, I wonder how the Coral compares to the XDNA-based IPU built into AMD Phoenix APUs. I imagine they'll make AM5 desktop version of them at some point, hopefully.
|
Posted By: duindain
Date Posted: 25 Oct 2023 at 5:30am
Someone in the community has made separate adapters that allow both units to work via pci-e or in a m.2 slot
I think they don't require bifurcation to work though there is some added latency, I was going to buy one soon since it seems a forgone conclusion that the motherboard only has the one lane
https://github.com/magic-blue-smoke/Dual-Edge-TPU-Adapter" rel="nofollow - https://github.com/magic-blue-smoke/Dual-Edge-TPU-Adapter
|
|