What We Recommend
Phenom II X4 940
Corsair XMS2 4 GB (2 x 2 GB) DDR2-1066
AMD Radeon HD 4870 X2
Samsung Spinpoint F1 1TB 7,200 RPM
PC Power and Cooling 750 W
AMD’s Dragon platform, though new in name, is the 790GX, which has been around for a while already. Thus, it was much easier to get all of the components for this one.
At the time of writing, the pieces for this platform add up to about $1,300—$250 less than the Intel-based configuration. The savings is substantial and will definitely have to figure into our conclusion. After all, you could get a Blu-ray burner in the AMD box with the difference, upgrade the processor’s cooling, or simply pocket the extra cash.
Overclocking Phenom II
In contrast to the known overclocking potential of Core i7, Phenom II is still uncharted territory. Sure, it drops into the same AM2+ socket interface as its predecessor, but it centers on a new manufacturing node and, according to AMD, incorporates all of the goodness previously enabled by the Overdrive application and ACC automatically. Those enhancements are baked into the hardware, AMD says. As a result, we’ve seen some fairly impressive results with the Phenom II on liquid nitrogen. But that hardly helps enthusiasts interested in one of these platforms at home.
AMD already seems to have a fairly good idea what a Phenom II X4 940 will do with air cooling. Somewhere between 3.6 and 3.9 GHz should be doable, according to talks we’ve had with folks in the company’s lab. We set our sights high and gunned for 3.9 GHz right out of the gate.
Overclocking with a Black Edition Phenom II is as easy as it was using previous Phenom chips—an unlocked multiplier remains the most straightforward way to scale up and down 100 MHz at a time on a 200 MHz reference clock. With 19.5x keyed in, we set the processor’s voltage to 1.55 V, which was the maximum AMD recommended for air cooling.
Blue screen loading up into Windows. That's a no-go.
Dropping down to 3.8 GHz with a 19x multiplier allowed us to boot into Windows, but starting any of our benchmarks resulted in a quick crash. We then tried 18.5x, yielding 3.7 GHz. At that speed (and after increasing the processor voltage to 1.625 V—which was far higher than we’d leave the system running), we were able to complete most synthetic and gaming benchmarks. But Call of Duty and the productivity-oriented tests just wouldn’t stabilize. We settled for 3.64 GHz by dropping the multiplier to 18 and adding 2 MHz to the reference clock (allowing us to also drop the voltage down to 1.6 V). That’s a better overclock than we ever saw with the 65 nm Phenoms, but not quite what we were hoping for with Phenom II.
The good news was that, even at 1.625 V, heat never seemed to be an issue, as Overdrive reported temperatures below 60 degrees Celsius throughout our suite. Then again, even the latest version of the software, as recommended for use by AMD, mis-reported our platform’s processor and memory clock speeds. Fortunately, we’re still more comfortable with BIOS overclocking anyway.