Rock 3A & google coral dual edge tpu

#1

Hello,
If anybody is interested in slot m.2 E for google coral setup I just tested that. Initial setup done via official page: https://coral.ai/docs/m2/get-started/
It dies when it comes to compiling DKMS module, to fix that additional step is needed:
apt-get install -y libssl-dev build-essential
cd /usr/src/linux-headers-$(uname -r)
make scripts
Once done, gasket module installs without problems. There were some other problems, on example parrot image test, but after adding user to gasket group and reboot all is ok and test is working as in instruction.
I tried DUAL EDGE TPU but there is only one pcie lane wired to slot and only one TPU is visible. Bofh may work with additional adapter: https://github.com/magic-blue-smoke/Dual-Edge-TPU-Adapter

Working tpu is hot, even when it’s not computing anything, cam interface makes it hard to cool, no air flow near it :frowning: I installed max version of lib and make some tests, with additional cooling it works ok.

Rock 3a support MSI-X?
#2

Hi,
Very interested in the information, especially M.2 E key supports for Single Edge TPU. Good to know.
DO you have a plan to test the DUAL EDGE TPU capability with M.2 M Key-PCIEx4 or M.2 E key-PCIEx1 adapter with Dual-Edge-TPU-Adapter?
Please add information of the result if you will have tried one of above.

Honestly, I expect an M.2 M key-M.2 E key adapter managing PCIEx2.
Thanks.

#3

I don’t have such adapter to test but it should work at full speed with m.2 M key (there are already two pcie lanes there). I’ll me using m.2 M slot for SSD.
E-key adapter is promising but probably it’s just better to buy and cluster two rock 3A SBCs with single TPU E cards.

#4

Thank you for your good advice.

#5

we have a wiki page for that:

https://wiki.radxa.com/Rock3/dev/install-coral-pcie-driver-and_edge_tpu-runtime-packages

welcome testing results.

#6

Can you take a photo of how your cooling is organized?
What kind of heat sink or fan did you use?

#7

Hello, I already moved this module somewhere and now I’m playing with wifi cards.
For cooling I used thermal pads and very simple radiator. Pad should be placed on bottom side too, there is poor airflow there thanks to camera connector, with pads heat is transmitted to rock3a board. Usually I place whole board in 52pi cluster case with large 12cm fan on front. I can place there up to 10 boards on this format, more often there are 8 because top is occupied by network card and power.

When I tested rock3a and edgetpu module outside that cluster case I used some small fan without pwm, just connected to gpio. EdgeTPU is hot even when not used intensively I know that some people use it without cooling but it may throttle. There are two packages for it, one with medium freqiencies and one with max, so it can reach up to 120 celsius.

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