It's going to be a lot slower, particularly with the goal of not slowing down a person's browser. By default, at least for me, their page is doing 1 hash per 200ms, or 5/second.

On the other hand, a quick Haskell implementation using Data.Digest.Pure.SHA is doing about 6,000 hashes per second (might have been 8000, I forget now) per core on an Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz

So you're looking at 1000 people to equal one core of a decent desktop. It's certainly an interesting approach, and has a lot of potential. I'm just not sure the marketing is there with the "help us win" motivation.

This JavaScript version: http://news.ycombinator.com/item?id=715014 (which doesn't do any throttling) is doing ~1500 hashes per second in one Chrome tab on my fairly old (2.8 GHz Pentium D) desktop. I'm curious how fast it would be on your Core 2 Duo in two Chrome tabs.

Im getting about 3100/sec, on my duo centrino2 / thinkpad

Mine peaked at 3,450 or so on a Core2 Quad @ 3.2Ghz

I think GPU's are going to win this "Yeah, my 5 GPUs are currently cranking at a total rate of 800 M/sec" they are are already looking at the low 30's.

Maybe a Google Native Client approach would have better luck. You would have to require your users be running Chrome, but it would be damn fast.

I don't think there would be much point, hah - JS will definitely be slower than optimized C. It's the crowdsourcing aspect that gives us a chance - it is very easy for anyone to just pull up the web page.

If you cook me up a simple tag that does the work in the background without any visual distractions I'll give you a couple of thousand hosts :)

have contributed 50k hashes now, will let it run through the night :)

good luck!

For unrelated reasons I recently did some benchmarking of SHA-1 in JavaScript vs Java. That particular benchmark was about 20x slower in the browser (both Chrome and Firefox 3.5) than on the JVM.

Not running C directly, but getting about 200,000 iterations per second running through an Nvidia GPU through CUDA and the Python wrapper PyCUDA.