Memory analysis and HEXUS.PiFast
Purely a synthetic benchmark that gives us an inkling in to how efficient the processors' memory-controller is at streaming data, we see that the Phenom lags significantly behind the Athlon 64 X2 6400+ and only just ahead of the Intel Core 2 Quad Q6600.
We're adamant that the comparatively poor performance is due to way in which the benchmark interprets the un-ganging of the memory controllers along with the fact that the MSI 790FX board had to be run with DDR2-800 memory.
Memory-access latency, a long-held virtue of AMD CPUs, again looks comparatively poor, contradicting all we've stated about the new architecture's improved pre-fetching design. Note, though, it's another synthetic benchmark that doesn't represent real-world performance.
Putting it all together and running our single-threaded HEXUS.PiFast test, we see that it takes a 3.2GHz Athlon 64 to match the Intel Core 2 Quad's performance. What's particularly telling is just how slow the Phenom 9600 is. Remember, it's operating at almost the same frequency as the Intel CPU.
Possible explanations for sub-par single-threaded performance? Our engineering-sample Phenom and early 790FX chipset BIOS may not be indicative of optimised performance, of course, but it's hard to dismiss and explain away such a shortcoming on production issues. Rather, the Intel Core 2 Quad's four-issue width plays a pivotal role in explaining the significant delta.