|AMD Phenom-II X6-1090T Black Edition Processor|
|Reviews - Featured Reviews: Processors|
|Written by Olin Coles|
|Tuesday, 27 April 2010|
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AMD Black Edition CPU Overclocking
When it comes to AMD processors, 'Black Edition' literally means overclocker-friendly. Benchmark Reviews demonstrated this in our overclocking tests with the AMD Phenom-II X4-965, which reached 4.2GHz. But that was then, two whole CPU cores ago. Six-core overclocking is all the craze these days, right?
Using the ASUS Crosshair-IV Formula ROG motherboard, overclocking was a breeze. I'm certain that AMD would have preferred we use their AMD OverDrive overclocking software for this article, but most enthusiasts prefer to go hands-on through the BIOS. It also doesn't help that we received the AMD Phenom-II X6-1090T only a few days before this article was published for product launch. So by using the ASUS Crosshair-IV Formula motherboard, it took changing only two BIOS settings to reach 4.0GHz with a 4.3GHz Turbo CORE overclock.
Benchmark Reviews will go into overclocking in more detail for our review of this AMD 890FX motherboard, but for early adopters who want a head start, I will share my secrets. AMD technicians shipped us the ASUS Crosshair-IV Formula with the AMD Phenom-II X6-1090T Black Edition processor already installed with a tweaked BIOS. Knowing that our tests needed to use 'vanilla' settings, the first step was resetting the BIOS configuration to the motherboard defaults. Next, go directly to the Extreme Tweaker menu, and set the AI Overclock Tuner to manual so you can manipulate the settings.
The first setting was simple: change the CPU Ratio (clock multiplier) to 20.0, which results in a 4.0GHz processor clock speed (20.0 x 200MHz = 4000MHz/4GHz). The second setting wasn't any more difficult, but requires CPB Control (Core Performance Boost) to be enabled. Once enabled I set the CPB CPU Ratio to 21.5, which generates a 4.3GHz Turbo CORE speed (21.5 x 200MHz = 4300MHz/4.3GHz). That's all there was to it!
But wait, there were a few pitfalls. For example, the version 0505 BIOS for the ASUS Crosshair-IV Formula motherboard allowed me to create any CPB CPU Ratio I wanted; even if that ratio was lower than the CPU Ratio. The one time I experimented with this, the system became unstable and Windows crashed. Hopefully ASUS will engineer future BIOS firmware with code that prevents using a lower CPB CPU Ratio than what the CPU Ratio is set to... or at least display a warning.
Voltages were managed by the motherboard, and each component was used the [AUTO] setting in the BIOS. In past experiments, setting the voltages to AUTO didn't always benefit the project. To my surprise, the ASUS Crosshair-IV Formula ROG motherboard took control and maintained complete stability throughout all of my benchmark testing.
I know you're still probably asking: why didn't he tweak the HyperTransport settings? The reason was just as simple as my overclocking changes: because this is a processor review. If I could change just two settings and create a 4.0/4.3GHz overclock, just imaging what the patient PC hardware enthusiast could do with a lot more time to test go/no-go settings! What makes this adventure even more enticing is that AMD mentioned that the HyperTransport 3.0 link can hit 2.6GHz on Thuben, which means there's plenty more headroom for added performance outside of the basic clock speed.