Tuning a graphics cards for top performance

Oct 10, 2010, 12:47 GMT

Hanover - With a few tricks and a bit of luck, it's possible to tease up to 20 per cent more performance out of many graphics cards.

Boosting the clock rate - known as 'overclocking' - is one well known way to achieve extra speed, at least for cards in the mid-range and performance classes, the German computer magazine c't recently reported.

Yet tuning, as this and other similar configuration tricks are known, can be a test of patience. It can take hours to determine the right clock rate so that the graphics card still runs stably without crashing or overheating.

Increasing the power supply to the graphics chip is not recommended because it increases power consumption significantly and, with more heat to dissipate, causes the fan to run more loudly.

Always back up data before tinkering with settings. It's also recommended that you install the absolute latest drivers for the graphics card and ensure that the card has detected them.

You should also install a programme to keep a constant watch over the temperature of the graphics chip, such as the free programme GPU- Z. The magazine suggests Furmark as freeware software to test the stability of the graphics chip under a high load.

Three different frequencies are important when planning on overclocking: the graphics clock (or core clock), the shader clock associated with the graphics clock, and the memory clock. GeForce and Radeon graphics cards can be manipulated with the relatively simple- to-use Afterburner tool from MSI.

Values are set once and then stored into profiles. If Afterburner won't work with your specific graphics card, then the tools from the card's manufacturer must be used, such as AMD's GPU Clock Tool.

Before bumping up the various parameters, first start GPU-Z and get a feel for the normal temperatures, voltages, frequencies and fan speed. Then use the Furmark tool to run a stability test, which deactivates full-screen mode, selects a smaller resolution than that of the desktop, sets the value 4x as the MSAA and starts the test.

You'll see a spinning donut on screen - and rising values in the GPU-Z window. If the graphics card doesn't fail in its tasks, then the memory clock is bumped up in 10 megahertz (MHz) increments. As soon as graphics errors occur in the spinning donut, the clock speed is reduced again.