Hallo, I've been running a Tor exit node on one of my machines (Intel Dual E2160 (1.8GHz), 2GB RAM, Xen domU for Tor, encrypted HDD) for some months. It is on a shared 100MBit/s line (500GB in/out daily). I have not configured any bandwidth limits within Tor.
Most of the time, the Tor process maxes out the CPU (85-100%), while memory consumption stays at ~10%; until today, this didn't pose much of a problem as log files show no errors and the machine has been used exclusively for Tor. I now want to play around with hidden services, and noticed that Apache takes a very long time to reply, even to local requests. As I am already using Xen, I thought it might be possible to share CPU and memory intelligently between two domUs (with the Tor domU having lower priority), but I didn't find any useful information how to do that. Are there any performance tweaks to limit Tor's CPU consumption? NumCPUs is set to 2, other than that I didn't modify the default configuration much. Also, niceness is set to +15 for the tor process. I want to avoid setting a fixed bandwidth limit, Tor should use "as much as it gets". Will upgrading the CPU help? -Daniel