(NOTE: this is NOT about client/vpn etc)
I have to upgrade my router (pre ac) and am trying to offload some tasks from a 24/7 PC. One of those tasks is a non-exit TOR node. running the tor service on a low(est) end AMD APU (5350) uses almost no CPU or memory.
I am now installing openWRT on a VM to check the existing support, but figured i might as well start this thread to learn if anyone already have experiences to share. thank you.
thanks vgaetera. My question is more related to openWRT (and the implied hardware) Maybe even later update https://community.torproject.org/relay/setup/guard/ with such info.
Does anyone found roadblocks? looking for experiences such as 128mb of ram not being enough for system+ssh+tor, Or such SoC having a hard time with CPU load, etc.
I'm currently running a hidden bridge on a WRT3200ACM. It uses a quite big chunk of memory, but CPU and bandwidth usage are minimal.
What speed does it reach? What is traffic per month?
I had a non exit tor node running on a (dedicated) Raspberry PI Zero, using an ethernet over USB gadget driver to connect it to my router.
A Zero has 512MB memory, but that was not enough on the long run. When disabling writes to the microSD tor was killed by the OOM killer within days. When keeping the microSD available for swap it was stable, and used around 300MB. But I assume it also has a higher peek usage, else why would it need swap space?
The CPU on the PI (800MHz Armv6) could perform 900kByte/sec throughput, which it sometimes did. The average throughput was around 1GByte/hour, which is about 300kByte/sec.
At the moment it's down, because for the 3th time in about a year the filesystem on the microSD is damaged.
I haven't measured it. I do not have any data caps, so I just configured TOR to use a fraction of my maximum bandwidth (100Mbps), and let it run. I could detect some connection now and then, but the traffic was really low, and stopped caring.
Those are interesting points. I will give it a try with my current modem before anything. It has some 40mb of ram not being used 
At the moment it's down, because for the 3th time in about a year the filesystem on the microSD is damaged.
I plan to also use the external USB drive as swap... one thing i would suggest is to give it the largest partition you can for swap so the kernel can write in a rolling fashion without having to reuse the same small portion over and over. You might be losing SD cards because of dead cells in a small region.