I bought a raspberry pi 3 recently and was wondering what kind of sync speeds I could get with one of those fast 90MB/s cards and the pi3's 1.2GHz 64-bit quad-core ARM Cortex-A53 CPU.
It seems like it could be usable for monero but I am not sure if its worth a try if sync speeds take ages or there are some other unwanted reliability, ease of use or whatever other problems.
Full disk encryption seems like a must though, that could slow things down a lot.
You could have a full secure environment with full blown linux environment on a chip the size of a cent bootable from the most cheap and commodity hardware there is.