Adequate PC Performance

There is much to be said pertaining to the expected performance of a PC that is to run WSPR/WSJT7. I have been running both of my Windows PCs (one is a 500 MHz PIII with XP Home, the other a 1 GHz Athlon with Vista Home Basic) for a few days now simultaneously running WSPR on both machines. I am amazed at the difference in captures with the fast PC. Not only do I catch more WSPR beacons, but weaker ones as well. The Vista PC has been capturing beacons at -24, -26...and even -28 dB.