StoopKid wrote:Is the raspberry pi capable of bitcoin mining without one of those USB miners? I know it would be slow and inefficient but I am looking at it from an educational standpoint rather than commercial. I have found dozens of tutorials but they all involve one of those USB devices. Are the really required or is it just not effective to be without them?
It is absolutely possible to do so-called cpu mining on the raspberrypi. For what performance to expect, here is a link to some arm processors: https://en.bitcoin.it/wiki/Mining_hardw ... arison#ARM
As for how to do it, it is a short project to set it up. Follow the instructions at: https://bitcointalk.org/index.php?topic=112098.0
As far as getting other than educational results, that is another matter. Here is my output fromthe executable, minerd:
[2013-09-24 13:25:19] thread 0: 7600064 hashes, 125.60 khash/sec
[2013-09-24 13:26:19] thread 0: 7475472 hashes, 125.32 khash/sec
[2013-09-24 13:26:22] LONGPOLL detected new block
[2013-09-24 13:27:23] thread 0: 7475472 hashes, 125.70 khash/sec
I am getting about 125 Kilo-hashes/second. A block erupter is rated at 333 mega-hashs/second, a ratio of about 1:2400 . Here are the results after running for a day at my mining pool:
Name 33 is a pair of block erupters rated 333MH/s x2=666MH/s; 720MH/s is reasonable. Name 22 is the rpi; 125KH/s does not register on the MH/s counter. However, after a day, the pi (22) has finally processed one work unit at the mining pool. Compare that to 8771 work units by the pair of erupter sticks.
Don't bother connecting to a mining pool unless you are already running another device that registers, and the pool must be able to split out individual workers so the pi's contribution can eventually be seen.
As an educational venture, take a look at the source sha256_generic.c for insight into how it works. The code is complicated by having to do the 256 bits in 32 bit chunks. This link https://126.96.36.199/index.php?topic=229052.0
provides a discussion of the hardware version of hashing.