On Fri, Sep 13, 2013 at 12:25:47AM +0200, Sarah Vigote wrote: > I would like to run a 100Mb/s tor exit node, but I have issues wrt > power consumption. > > reading > http://ortizaudio.blogspot.fr/2011/10/using-dreamplugs-crypto-chip.html > it seems dreamplugs has *fast* aes-128-ecb. > > Does anyone have any experience running a node based on cheap crypto > chip (dreamplug, marvell 88F6282, sheeva-core, padlock, ...) ? What > performance can I expect out of these ?
Unfortunately AES is not the primary CPU consumer on Tor nodes right now; we spend a lot more time doing bignum computation for TAP circuits. Crypto accelerators don't work very well for bignums. It's not a perfect equivalence, but "openssl speed rsa" should give a reasonable estimate of how well your chip will do for TAP circuit creation. Here's a dual-core Westmere at 2.1 GHz (should be fairly close to a modern Xeon core): sign verify sign/s verify/s rsa 512 bits 0.000105s 0.000007s 9548.7 137778.7 rsa 1024 bits 0.000340s 0.000021s 2941.1 48539.0 rsa 2048 bits 0.002205s 0.000070s 453.4 14362.8 rsa 4096 bits 0.016398s 0.000260s 61.0 3840.3 A single Xeon core can currently handle most of a 100 Mbps exit node's traffic, so you should look for a dual-core chip that delivers at least 1500 sign/s on rsa-1024. Unfortunately I doubt there are any ARM chips that can compete. -andy _______________________________________________ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays