Mining Primecoin XPM with threads > cores

[hasle2]

Ok so I have to ask this in the newb section.

I have been using Chemisist's optimized version of the primecoin miner and have been running twice as many threads as cores. Some people have been claiming that this could cause problems with the mining algorithm and slow mining down. I'm wondering if anyone has any hard numbers yet?

It sounds like measuring the mining rate is not that straight forward right now and I do not know how to do it myself.