So we can set up three kinds of overclocking: increasing the clock at which the video processor runs, increasing the clock the video processor uses to communicate with the video memory and increasing the clock the motherboard uses to communicate with the video card. You can even perform these three options at the same time in order to explore the maximum performance your video card is able to provide you. The first two overclockings are done configuring the video card and you can change these two clocks on any video card, while the third one is done on the motherboard setup and it will depend whether your motherboard provides this configuration option or not.

The first thing you need to do is to discover the core clock and the memory clock your video card is currently using. The best way to check this is using a program called PowerStrip. This is also the program we will use to overclock the video card. Depending on the version of the video driver you are using, it can provide the same functionalities of PowerStrip – including overclocking. Since we cannot tell for sure if your video driver has this feature, we prefer to use PowerStrip.

Running this software for the first time you will see the clocks your video card is really using right away. From the second time on, PowerStrip will start minimized on System Tray and you will need to right click on its icon and choose Performance Profiles, Configure.

Pay attention as for ATI-based video cards PowerStrip will report the real memory clock but for nVidia-based video cards it will report the DDR clock (real clock x 2).

Let’s see two examples. On Figure 2 you can see the clocks used by our Radeon 9800 Pro: 378 MHz for video processor ("core clock") and 337 MHz for memory. And on Figure 3 you can see the clocks used by our GeForce 6800 GS: 425 MHz core and 1,000 MHz DDR memory.

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Figure 2: Clocks used by a Radeon 9800 Pro.

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Figure 3: Clocks used by a GeForce 6800 GS.

You can compare the clocks your video card uses with the manufacturer’s default clock for your video card. Click here to take a look on our ATI Chips Comparison Table or click here to take a look on our nVidia Chips Comparison Table. Please notice that the memory clock rates on these two tables are “doubled” (i.e. DDR).

As you can see on our table, Radeon 9800 Pro has default clocks of 380 MHz for core and 680 MHz DDR (340 MHz x 2) for memory, and GeForce 6800 GS has default clocks of 425 MHz core and 1,000 MHz DDR (500 MHz x 2) for memory. As you can see, our two video cards were using the default clock rates set by the chip manufacturer. Small differences below 5 MHz are normal and that doesn’t mean that your video card is running at a “wrong” clock rate.

Sometimes you will find that your video card is factory-overclocked, meaning that the manufacturer has already set it to run at a higher clock rate. Even if this is your case, you can try to overclock your video card even more.