upgraded PC=low performance

if anyone has an idea, pls help
it goes like this- till last week i was playing on my pc-specs-mobo asrock k7, cpu sempron2600 working 1,7 ghz, 2G ddr 400, video ATI 9500 256ram pixel shader 2, OS win 7 ultimate.PC rate:4.5. i had always 55-60 ping in uk server and 145-155 in alpha with 60-80 fps in 8v8 room. this PC broke last saturday.
I got another PC- mobo intel,cpu intelpentium4 working 3,2 ghz, 2 G ddr 400, video nvidia 7300 512 ram pixel shader 3, OS win 7 ultimate. PC rate: 5.1. Now i have 10-15 fps in 8v8 room, 70-100 ping in uk and 180-220 in alpha.
i just dont get it. i dont have any other games instaled since this second pc is just 4 days old, clean instal, aditional software installed: avast antivirus, openoffice suite, vlc movie player and yahoo messenger.everything is working fine, it works faster- like on the intrnet- videopages are loading very fast( ex youtube, i can watch online video streaming on other sites with no delay- which i coulnd on my first pc), download/upload on diferent sites is faster, i can work with at least 15 tabs opened in internet browser(both IE8 and Firefox). Only crossfire game works very very slow/bad now. I even turned off aero, configured low-basic appearance in windows , shut down the antivirus and configured the video card for performance only- low texture , low detail, 3D option on demand by application, 800x600 resolution for crossfire, no weather effects ingame and so on. The only good thing was i got some extra 5-10 fps, ping remain the same 70-100 in uk and 180-220 in alpha
I think the specs are way better on my sec pc.My internet conection is the same, broadband 50Mbs( thats what it says on the contract- dont know the actual speed- but it must be the same it was for 5 years).
thanks for reading- pls, if anyone has an idea-apart from me getting a core2 or i7 processor pc..