OverDrive’s Results and System Setup

Overclocking

Right off the bat I went with OverDrive’s Auto Clock feature, which incrementally increases the board’s reference clock to the point of instability, then backs down to the last known successful frequency. The strategy is hardly dynamic—I didn’t see any voltage increases or multiplier tweaks (the whole point of buying a Black Edition processor). Nevertheless, OverDrive settled on a 210 MHz HT clock, yielding a 2415 MHz CPU frequency. As a very blunt tool for pounding out free megahertz, Auto Clock does its job.

I was looking for something a little more elegant, though. After switching into the Advanced mode, I started by bumping the Phenom 9600 up to a 12.5x multiplier, up from 11.5x. I gave the chip an extra .1V of juice and proceeded to run OverDrive’s built-in stability test. So far, so good at 2.5 GHz. Then I bumped the reference HT clock up 5 MHz, targeting a 2.56 GHz CPU clock. Immediately, the machine locked up. Oops. Perhaps that was a little much.

I went back and dropped the multiplier to 12x and sought a bit more horsepower from the HyperTransport interface, bumping the reference clock to 208 MHz. Again, I was looking at a 2.5 GHz CPU clock. Now the system also had extra speed from the memory, northbridge, and HyperTransport 3.0 connection, too.

Just to make sure the OverDrive settings were good to go, I applied the settings and restarted the test bed. OverDrive loaded back up and—what’s this? My adjustments had all reset? Ah ha; OverDrive Assist hadn’t yet been enabled. If you want your overclocked settings to be applied automatically, you’ll need to have that feature turned on.

Once it came time to start running benchmarks, the OverDrive-enabled configuration proved unstable, failing to consistently load the clock multiplier settings I had chosen and freezing up upon launching certain tests. Back to the BIOS I went, manually configuring the settings to match what I knew worked. In the end, I decided to stick with a 12.5x clock multiplier and stock HT setting. Interestingly enough, even with a pair of DDR2-1066 modules running at pre-configured SPD settings and pumped up with an extra .5V, I couldn’t get the platform stable using a 5.33x memory multiplier. The results were much better at DDR2-800 frequencies and more aggressive timings. Looks like the BIOS is still your go-to once you’ve figured out the best possible combination of settings with OverDrive.


Don’t think that OverDrive will save you from ever digging into your board’s BIOS, even if you do use it as a primary overclocking platform. The Gigabyte MA790FX-DS5 board we used for testing came loaded with software features, including a switch for disabling the TLB erratum, Cool’n’Quiet control, and a virtualization toggle. The board’s MB Intelligent Tweaker screen gives you control over the same knobs and levers as OverDrive, so if you’d rather overclock that way, there’s no shame in going old school. Not all AM2+ boards are going to be as enthusiast-friendly, though. Should you find yourself constrained by your vendor’s choice in BIOS settings, OverDrive is a real savior.

For what it’s worth, it may turn out that some motherboard vendors don’t give you an option to turn off that TLB erratum workaround, since it can cause stability issues under heavy load, according to AMD. If you find yourself on a system without the option to disable the patch, simply head into OverDrive and click the little green button in the upper right-hand corner of the utility. Based on our experiences with the Gigabyte board and its BIOS toggle, when the patch is enabled (thereby hammering performance), that button is green. When it’s yellow or red, the patch is off. Tech Report’s Scott Wasson reports that when the button is red, there’s also a CPU-based power management option being disabled to further enhance performance.

System Setup

AMD Phenom 9600 Black Edition (2.3 GHz)
AMD Phenom 9500 (2.2 GHz)
Intel Core 2 Quad Q6600 (2.4 GHz)

Gigabyte MA790FX-DS5 Motherboard
ASUS P5E-VM HDMI Motherboard

2GB OCZ Technology DDR2-1066 CAS5 Memory (2x1GB)

Gigabyte GV-RX387512H Radeon HD 3870 512MB

Seagate Barracuda 7200.11 1TB SATA 3 Gbps Hard Drive

Windows Vista x32, current as of March 13th, 2008 with Windows Update

DirectX 10

Desktop resolution 1600x1200, 32-bit color, 85Hz refresh

We disable Vista’s UAC and generate an image using Norton Ghost 11 to create the same basic benchmark platform for each test bed. The image is frozen with the latest Windows Updates and deployed to each system. The appropriate drivers are then loaded to the machines.

Benchmarks

3DMark06
Unreal Tournament III
Lost Planet: Extreme Condition
Half-Life 2: Episode 2
Company of Heroes
Call of Duty 4