According to 'openssl speed aes-128-cbc' the Allwinner A20 CPU in Banana Pro is capable of about 25 MBytes/sec in AES performance. While that won't translate 1:1 into Tor performance, as Farid noted in his case the CPU isn't being a bottleneck, with only 10-20% CPU load observed.
I don’t understand very well this fact, but CPU can be the bottleneck even if load or CPU usage not at full capacity.
One of my Tor guard relay have the same CPU behaviour (see screenshot enclosed). 2 instances at 50-60% CPU usage (as reported by htop), load around 0.70-0.80 (4 cores), RAM at 20% (400MB/2GB) but bandwidth not saturated (20Mbps only on a 200Mbps line). Perhaps because of the multiple changes of context (AES crypto, Tor software logic, network IO…) and so a lot of wait/IRQ (as visible on the screen) and not a fully used CPU.
Also seems unclear why it didn't get the guard flag for so long, does your public IP address change from time to time? Or do you turn the relay off and on for whatever reason.
Perhaps a low bandwidth ? Babylonian seems to be on the lower part of guard relay (2146/2313), possible it hadn’t enough bandwith before end of august to get guard flags ? Only the 25% fastest relays can get the guard flag. Today it’s around 2.5 MBps advertised / 1MBps measured. Babylonian is just at the limit (2.45MBps advertised, 600kBps measured).
<3,
