Couldn't find anywhere to make a new topic on the forum (probably because I'm a n00b).
I've been solo mining, initially with the official Primecoin client, and now, for the past 24 hours, with mikaelh's Primecoin hp5 client from here:
I've run both the original and hp5 on a number of different processors and found the hp5 release increases PPS anywhere between 4 and 10 times depending on the processor.
My PPS on hp5 are as follows:
~750 PPS with i5 M460 2.53GHz
~1900 PPS with i5-3317 1.7GHz
~4800 PPS with i7-3610QM 2.3GHz
~10500 PPS with 2x Xeon X5650 2.67GHz
All the above PPS were obtained using the 'getmininginfo' command after the mining process had been running for 10 min or more. Mining was started using 'setgenerate true -1' in all cases. It seems that the PPS statistic is only updated once per block and there is a variance of about 5%.
Sadly, the higher performance of the hp5 client hasn't increased my luck. I've only found 1 block so far, and that was while running the original client.
My job brings me into contact with a wide range of CPUs, so while CPU mining XPM is still viable I'll update this post when I test Primecoin mining on others. It's more fun than stress testing them overnight with Prime95!