I'm running a 1600xp pal. @1.85Ghz but my psu is limiting me. Thats the best speed I can get until my psu just won't give it any more power. I have 300 watt and it won't give any higher than 1.8 core. My temps are 35 idle and 38-40 load so it's not the cpu that is the problem, just psu. What psu is recomended?