Yeah, I'm using HP8 right now. Over the last few days the rate seems to have dropped off as the difficulty was increasing, but the difficulty has been decreased a bit so I might get more blocks now. We might not have much luck though since there are some gpu miners in the works. Honestly I have been using settings lower than the max speeds that I have available over the last few days since with a sievesize of 100k I haven't managed to get any blocks - I only have gotten blocks with a 1m size so far. Once the gpu miner hits we will be getting that 19 days/block quote there though. The difficulty is probably going to explode...
Also I have noticed it's really random when you get blocks - I have one machine that's getting 1k pps and it managed to get a block and one that gets about 4k or 5k hasn't managed to get one yet.
It's probably just random, despite the faster machines SHOULD get more blocks mined. But the lottery is the lottery.
I am using a sievesize of 100k too because I noticed it gives me a faster PPS rate. Is a lower sievesize actually worse, despite the higher PPS?
I'm not a skilled enough mathmatician to explain this fully, but this should give you a rough idea in terms you can understand. Let's say you have 100,000 US coins of all denominations, and you are only looking for 1972 pennies. Now, think of the sieve as a massive coin sorter. You toss in this 100,000 coin bunch of pennies, nickels, dimes, quarters, half dollars, silver dollars, Susan B's, etc. You're only looking for pennies, so you 'sieve' this mass of coins down to pennies. These candidates (pennies) are then subjected to the Fermat test (date check) and you only pull out the 1972's.
So, the smaller the sieve size, the faster you can go through it, but you'll find fewer total primes in the long run.
