Processor is an AMD Sempron 145. I know it is slow but didn't think anything faster was needed when graphics cards are doing the mining. Was also trying to not use as much electricity with this processor. Anyway, so I need a faster processor?
Unlock the other core if you can. One of my all Tahiti rigs uses the same CPU, and it was a real slowpoke with this miner until I realized it was the CPU holding it back and I hadn't unlocked both cores yet. That machine is now mining much faster.
Not a problem on my Intel rigs, though the 7 card rig isn't mining to its full potential yet. I suspect that one could use more CPU as well - it's a mixed Tahiti/Hawaii/Pitcairn rig. Incidentally, that one is more stable with 0.4.2 than 0.5. 0.5 will mine for a minute or two and then the cards drop out one by one.
I just did a fresh rig, moving all my card from the old E2160 to the "new" 145 cpu rig
and I'm going to OC the cpu to 3.5 and see if there is any improvement
otherwise I am considering grab a 6300 to support those GPUs and I guess itself can hash about 14S/s