To give you guys a "real" idear about the odd and timing, it might be a good idear to read the wiki
time = difficulty * 2**32 / hashrate
where difficulty is the current difficulty, hashrate is the number of hashes your miner calculates per second, and time is the average in seconds between the blocks you find.
source:https://en.bitcoin.it/wiki/Difficulty
the current difficulty is 75,5 T, that's 75.500.000.000.000
You can get to run your sidehack R909 @ 2,1 Th/second
when you're talking about a cpu or a gpu, you can look here:
https://en.bitcoin.it/wiki/Non-specialized_hardware_comparison, but the fasted cpu hashes @140Hh/s and the fasted GPU @2568 Mh/s (those numbers are acutally quite old, but i would be supprised if new cpu's and gpu's have a SIGNIFICANT difference in the outcome of the calculation)
So, a lottominer, the R909:
time = (75.500.000.000.000 * 2**32)/ 2.100.000.000.000 = 1.544.143.004.038 seconds = 25.735.716.733 minutes = 428.928.612 hours = 17.872.025 days = 48.964 years
So, on average, at current difficulty, it would take you about 50 thousand years to hit a block with an R909So, a gpu:
time = (75.500.000.000.000 * 2**32)/ 2.568.000.000 = 126.273.376.498.442 seconds = 2.104.556.274.974 minutes = 35.075.937.916 hours = 1.461.497.413 days = 4.004.102 years
So, on average, at current difficulty, it would take you about 4 million years to hit a block with the "best" gpu in the benchmarkSo, a cpu:
time = (75.500.000.000.000 * 2**32)/ 140.000.000 = 2.316.214.506.057.142 seconds = 38.603.575.100.952 minutes = 643.392.918.349 hours = 26.808.038.264 days = 73.446.680 years
So, on average, at current difficulty, it would take you about 73 million years to hit a block with the "best" cpu in the benchmarkThere are all averages offcourse... yes, in theory, there *is* a chance of hitting a block with an rpi whilst cpu mining for a couple of seconds... The thing is that people are very bad in interpreting the odds, as long as they see a number and the word "average", they think there's an actual possibility of hitting a block with a cpu/gpu, whilst in reality their odds are sooooo small, they are so close to zero that you can probably just round them down to zero to begin with... You'd probably have better odds of getting married, going for a swim before the ceremony, being bitten by a shark at the same day as being hit by lightning, winning the lottery and getting into a car crash on your way to the hospital (i didn't do the exact math tough).