I've got arround 200 mbits with an Intel Xeon E3-1230v2 (not over 30% total cpu usage - 1 core at ~100%).
Pretty slow for an dedicated gigabit connection, due to this fact i've killed my nodes.
The ticket for this "problem" is still not solved, after 3 1/2 years. :[

quote from the ticket(would sign that):

May I suggest to get this at critical priority?
21th century crypto software can't afford to be not fully-threaded ;)
No CPU sold today is mono-core anymore, and I sure few people would run a tor dedicated relay up 24/24 to see it used at only 1/n'th of its capacity.

On Jan 24, 2014, at 10:49 , Alexander Dietrich wrote:


Hello,

a relay I'm running is currently at about 0.80 load average. It has a dual-core CPU and I have configured "NumCPUs 2". I'm still in the process of finding the bandwidth limit.

Should I keep increasing "RelayBandwidthRate" on the single Tor process, or is it a better idea to start a second process?

In my experience, CPU load does not depend much on the amount of traffic, but much more on the number of connections/handshakes. 
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