Overclocking does speed up your crunching. Running at 2.6 instead of 2.2 would net you around 18 percent more work done per unit of time(hour, day, etc) and a correspondingly 18% increase in points per unit of time. 18% isn't a great amount so it would take some careful monitoring of your stats and benchmarks to see it.

I have a couple Opteron 165's running at 2.8GHz which crank out about 5100 points per day each. At stock speed (1.8), they only do about 3300 points per day.

Incase you are wondering, only CPU speed seems to be important when crunching on WCG. Overclocking the RAM, front side bus, or tightening RAM timings has very little, if any effect.

I got the 238x11 part (20% - not bad). What's the 23361t?

How did you test?

Just curious.

Did you re-run the BOINC benchmarks after overclocking? They only run every 5 days on their own. Check your benchmark scores at 2.2GHz and at 2.6GHz. If you're not seeing an approximate 18% increase in benchmark scores then I'm not sure what is happening.