In the purpose of setting up a Tor relay that makes good use of a fast FTTH connection, what computer will do the job most efficiently at the time of writing, provided the following requirements are met?
- best bandwidth usage / power consumption ratio
- must run Linux, any flavor of it but preferably GNU / free software (proprietary blobs not encouraged)
- low budget, let's say less than 250 US dollars?
The real capacity of the Internet connection is not known, but possibly capped at more than 1 Gbit/s. Not all the bandwidth needs to be made use of, speed / power ratio takes precedence.
Single board computers (Odroid, Raspberry Pi...) seem to be the winners at first sight. However I would like to get answers based on the specifics of Tor reference implementation, which I have no clue about. Would it benefit more from higher CPU clock frequency? Multiple cores? Bigger RAM? What does Tor need the most?
I tried to identify some of the basics:
cryptographic routines need:
- fast CPU
- is Tor optimized for specific instruction set (NEON, SSE, AVX...)?
- is Tor optimized for several cores?
connection management need:
- Gigabit link
- lots of memory (2GiB as a bare minimum?)
- big CPU cache