Hi all, I'm new to cryptocurrencies and I'm trying to learn as much as I can.

I think I've arrived too late to gain some BTC or LTC, so I'm trying to understand and deal with new cryptocurrencies like primecoin XPM.

I like the fact that (atm) XPM is only cpu minable. Where I live the electricity is very expensive so gpu minig is prohibitive considering also the high and quickly increasing difficulty (correct me if I'm wrong).

Quick questions for you:
1 - I can use 3 systems: 2 core i7 (8 threads) and a double xeon (16 threads). Do you think that's better solo minning or joining a pool (like ypool)?
2 - Is there some sort of guide that explains what are and how to properly set sieve size and percentage (and, why not, other miner parameters)?

Thank you in advance and excuse me if I've made dumb questions.