from a Pentium dualcore 2.8ghz to any Core2 Extreme qx9- - - is already a big upgrade, you can see the difference even if core2 quads are not the latest today because it has 4 cores than your pentium d 2 cores, and is a newer cpu models to that pentium dualcores. if you can spend much go for the Core2 Extreme QX9770 or Extreme QX9650, if your on a tight budget then you can get the Core2 Quads 9650, 9550, 9500.