Hi, Slahr Dzhe. I remember you; I just missed you the first time around as I've cooled off on DC too. But I just got a new Q9400 to replace my old Athlon XP (
that's old!), and now that I can actually get results with
PrimeGrid, I'm more into it at the moment.
If you're not overclocking that E8400, you should look into undervolting it. My Q9400 was able to go down nearly 0.1V, and went down a good 5-6 degrees in temperature. If you can run a Prime95 torture test stably for at least an hour or so, PPS LLR (not to be confused with PSP LLR) has small, fast work units that can get you
a top 5000 prime. If not, sieving won't heat your CPU as much, and might get a little more BOINC credit.
I'm sure there are lots of other good projects for you, but like I said, I haven't been paying much attention lately.