Overclocking AMD's Phenom II X3 720 BE

Asus M4A79T Deluxe

The Asus M4A79T Deluxe is an evolution of the AM2+/DDR2 M3A79-T Deluxe we liked very much. We've already looked at the M4A79-T and found it follows in the same stead with a great BIOS that's easy to navigate and has plenty of options that are clear and work well. The board features an 8+2 phase CPU power circuit with support for 140W Phenoms - so plenty of overhead for our 95W triple core - as well as the Asus EPU² technology. This was disabled for our overclocking experiment, though.

Asus's Precision Tweak affords 16 steps for CPU-NB voltage adjustment, 50-steps for DDR3 memory and 0.0125V increments on the CPU voltage too. Despite this we could only hit the common 3.7GHz on all of the CPU cores, but like the Gigabyte below the Asus wouldn't exceed a stable overclock of 2.4GHz on the CPU-NB when we came to stress it.

We found AMD's OverDrive 3.0 software works better with the Asus than the other boards by actually allowing adjustments for memory, 790FX-NB and southbridge voltages, but there are still inherent limitations like the lack of CPU-NB performance adjustment.

Gigabyte MA790FXT-UD5P

At the time of testing, despite the fact we've gone through a half dozen Gigabyte BIOSrevisions - including the F3l that promises better overclocking - as well as two different UD5P motherboards, we found this was the most limited when overclocking our 720 Black Editions. With limited BIOS options for voltage tweaking (using +voltages rather than absolute values for CPU and CPU-NB), poor voltage descriptions, and coarse adjustments of no less than 0.1V, we feel the Gigabyte MA790FXT-UD5P just doesn't unlock the full overclocking potential of these CPUs.


With a similar 8+2 CPU power design like the Asus above with large heatsinks strapped to it, it should afford just as much overhead. However, while mostly stable at 3.7GHz CPU core, it would staunchly resist any attempt over this frequency, whereas at least the MSI would boot into Windows at 3.9GHz for example. More importantly the differentiators came from the CPU-NB that failed to even run at 2.4GHz stable on any of our 720 Black Editions, despite endless voltage tweaking. Compared to the MSI that runs a stable northbridge frequency of 2.6GHz, with 2.8GHz within reach under some limited conditions, and the fact AMD's OverDrive software wouldn't apply any other voltages other than CPU and CPU-NB, the Gigabyte is clearly lacking.