This has been discussed before, try searching the archives with something like
"AccountingMax vs RelayBandwidthRate".
I think teor gave a very good answer here:
https://lists.torproject.org/pipermail/tor-relays/2015-May/006956.html
The technique you'll want to use really depends on whether you want a faster
relay for part of the month, or a stable (but slower) relay throughout the
month. Teor goes into more detail in that post.
_______________________________________________
tor-relays mailing list
tor-relays@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays