Amd Cpu Comparison Cpu Speed Comparison: P4 3.4Ghz Vs Pentium D 920 Vs Dual Core2 6300 Vs AMD 4000+?

Cpu speed comparison: P4 3.4Ghz vs Pentium D 920 vs Dual Core2 6300 vs AMD 4000+? - amd cpu comparison

Comparing the speed of the CPU: P4 3.4 GHz vs Pentium D 920 Dual Core 2 vs AMD 4000 + vs 6300
Who is faster? I have the P4, but not to a significant speed penalty compared to friends, the Pentium D 920 and Pentium 6300th After reading the benchmarks online, sometimes I wonder why my great data from Excel spreadsheet ready processed almost one second faster than the two mentioned later? I DIY upgrade to AM2, AMD 4000 + is the value?