I was looking on blockchain explorer of Primecoin. And I wonder
https://bchain.info/XPM/addr/AZtxQr2FMR4PURkVAAuK17mDJ17grUWrUzLook at this address. This person mostly
GENERATE coins, so
he is solo mining. At difficulty 11 I doubt that Claymore miner is efficient since it works only on older drivers with older cards. But this is not whole story. When I do solo mining with Claymore miner , on every block I found I pay fee for Claymore and that was visible on my transactions.
On those blocks, however there is NO fee for everyone. So this person has solo miner, working on newer drivers , and obvious this miner is not public available. Second if you look at confirmations he found many block one by one: so he must have HUGE number of GPU ( maybe it is ASICs miner) or his miner software is way faster then public one.
It looks like, we all using pools and available software miner is cheated in some manner, and that is not good