The PCMark and 3DMark benchmarks test the entire system with the 3DMark series being more graphics intensive. As my X4 940 system uses XP as its operating system, I was unable to run PCMark Vantage or 3DMark Vantage, and I was unable to run PCMark05 on the X3 720/ M3A785GMH/128M system because that program does not support Internet Explorer 8. (PCMark05 uses IE for page rendering and other tests) So I was unable to compare the X3 system with the X4 system in Futuremark testing in those tests. As my X4 rig uses a much less powerful video card than I have in the test rig, I saw no benefit in comparing the two rigs with 3DMark06.
Testing - PhotoShop
Next I ran a real world test using PhotoShop CS3 and PSBench by Driverheaven.net. PhotoShop Bench consists of a script that runs a series of filters on a large .jpg, and you compare the times it takes to perform each filter operation. There are 15 steps, I chose a few of the ones that take longer to complete, some operations take only a second or two and really don't show significant differences.
Here in real world testing, the X4/790G outperformed the X3/M3A785GMH/128M at stock clock, but overclock the X3 and it is the clear winner in every test.