The other components were 2GB of OCZ Reaper PC2-9200 memory, a Hitachi 7K1000 hard drive and a Sapphire X1950 GT graphics card with Windows XP SP2. We ran three tests; PCMark05, 3DMark06 and DVD rendering with a 350MB AVI file in Nero 7. 3DMark06 is almost exclusively a test of the graphics card but it also shows up glitches in system performance, PCMark05 tests the whole system and gives a break-down of the sub-systems, while video rendering is a pure test of the CPU.
First up was a 2.6GHz Athlon 64 X2 5000+ which gave us base line figures, followed by the X2 6400+. The AMD model codes suggest that an X2 6400+ is 28 percent faster than the 5000+ however the 3.2GHz clock speed of the X2 6400+ is only 23 percent faster than the 2.6GHz of the X2 5000+. The overall result in PCMark05 gave the X2 6400+ the nod to the tune of a little over 14 percent while the CPU element of the benchmark rose by 23 percent, which is exactly in line with the clock speeds.
In the video rendering test the X2 6400+ rendered the movie nearly 20 percent faster than the X2 5000+. As the two X2 CPUs share the same L2 cache and data bus it is a mystery why AMD sticks to its absurd model codes when it is clear that the X2 6400+ is more akin to an X2 6150+, and that's only if you take the X2 5000+ at face value.
It's all well and good comparing one AMD processor with another but anyone contemplating a new CPU should be considering a Core 2 Duo so we plugged a Core 2 Duo E6750 in to a Foxconn G33M-S motherboard with the same memory, hard drive and graphics card. The E6750 runs at 2.67GHz on a 1,333MHz FSB and costs £126 at Overclockers so it is cheaper than the X2 6400+ and nominally it is slower.
The results of the tests clearly show that the E6750 is four percent faster than the X2 6400+ in PCMark05 and is 12 percent faster in the graphics rendering test but that's only half the story. The Athlon 64 X2 can be overclocked by a small amount if you work very, very hard at the job but the Core 2 Duo overclocks like a dream. We cranked the 1,333MHz FSB on the E6750 to 1,600MHz to give a clock speed of 3.20GHz which dropped the video rendering time to seven minutes 59 seconds and raised the PCMark05 score to 7896, and all that on standard voltages with a nice quiet CPU cooler.
The Athlon 64 X2 6400+ takes the K8 family of processors to new and unexpected heights but the cruel truth is that it's completely overshadowed by Intel's Core 2 Duo which is better in every department.