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Overdrive

One of the new features in the XT line of cards from ATI is the presence of an onboard thermal diode. This allows the drivers to overclock the videocard automagically when it is in a certain temperature range and throttle it back down if it gets too warm. From our friends at ATI we found out that Overdrive will clock the VPU core up to 419 mhz if it is below 56° celsius and temperatures above that will result in the default clockspeed being used. The upside is that the clockrate never drops below the default 412, the downside is that the actual overclocked speed is miniscule. By miniscule, we mean that this is probably something you will not notice during gameplay.

While Overdrive is a nice feature especially for those who are leery of overclocking, it would be much preferable for ATI to have included a Coolbits type utility like Nvidia so the more experienced end user can have more control over the clockrates without having to resort to third party utilities. Overdrive the way it is now, is more of a marketing gimmick than a feature that will bring substantial performance gains.

ATI may want to take a look at AOpen's SilentTek feature on their motherboards (which we like very much). One of SilentTek's modes allows the end user to set the fan speed to a certain level depending on the temperature of the CPU. It would be great if ATI could do the same thing with regards to clock rates- have the VPU adjust to an user specified clockrate depending on the temperature. Not only could the end user overclock their card, but they can do so in a safe manner and if the videocard heats up to a point where the end user starts getting leery, the Overdrive software can kick it back down a notch. Overdrive has great potential and hopefully ATI will implement something in later driver revisions that will really take advantage of it.

A couple extreme close-ups of the heatsink