[tor-relays] Tiny computers (RPi-like) for exit nodes?

[Michael McConville]

Roman Mamedov wrote:
> On Thu, 18 Aug 2016 10:40:00 -0600
> Michael McConville <mmcco at mykolab.com> wrote:
> 
> > Zack Weinberg wrote:
> > > Has anyone had any experience running *exit* nodes on Raspberry
> > > Pi-grade hardware, or slightly beefier?  We are thinking of
> > > replacing the old, bulky, power-hungry machine currently running
> > > exit 78C7C299DB4C4BD119A22B87B57D5AF5F3741A79 with something on
> > > that level. It only has to hit 10Mbps.
> > 
> > There's only one way to find out, but I suspect an RPi would be too
> > weak for the job. Exits use more CPU because they manage far more
> > TCP/UDP connections than a non-exit relay. I've seen significant CPU
> > usage (maybe even CPU saturation) on a cheap Intel Core Duo moving
> > about 3-5 MB/s.
> 
> Raspberry Pi 3 should do fine, not to mention some of the more
> powerful boards -- there are now up to 8-core, up to 1.7 GHz ones.
> Even though the core number won't help you too much, you shouldn't
> underestimate what a modern 64-bit ARM can do. Especially if the task
> at hand is mere 10 Mbps.

I'd be happy to be proven wrong. However, remember that while 10 Mbps
doesn't sound like a lot, it can imply 7,000+ open connections. That can
stress the kernel and the CPU cache.