HIS Radeon HD 4870 X2 2048MB review - 15 - Overclocking & Tweaking

Overclocking & Tweaking

As most of you with most videocards know, you can apply a simple series of tricks to boost the overall performance a little. You can do this at two levels, namely tweaking by enabling registry or BIOS hacks, or very simple, tamper with Image Quality. And then there is overclocking, which will give you the best possible results by far.

What do we need?
One of the best tool for overclocking NVIDIA and ATI videocards is our own Rivatuner that you can download here. If you own an ATI or NVIDIA graphics card then the manufacturer actually has very nice built in options for you that can be found in the display driver properties.

Where should we go ?
Overclocking: By increasing the frequency of the videocard's memory and GPU, we can make the videocard increase its calculation clock cycles per second. It sounds hard, but it really can be done in less than a few minutes. I always tend to recommend to novice users and beginners not to increase the frequency any higher then 5% of the core and memory clock. Example: If your card runs at 600 MHz (which is pretty common these days) then I suggest you don't increase the frequency any higher than 30 to 50 MHz.

More advanced users push the frequency often way higher. Usually when your 3D graphics start to show artifacts such as white dots ("snow"), you should back down 10-15 MHz and leave it at that. Usually when you are overclocking too hard, it'll start to show artifacts, empty polygons or it will even freeze. Carefully find that limit and then back down at least 20 MHz from the moment you notice an artifact. Look carefully and observe well. I really wouldn't know why you need to overclock today tested cards anyway, but we'll still show it ;)

All in all... do it at your own risk.

The default clock for this product is 750 MHz on the core, we ended at 800 MHz. The memory however was extremely promising. ATI reference default is 3600 MHz(900x4), we could push it easily towards 1000 = 4000 MHz sustained memory bandwidth data rate. However we stopped after that, as the overclock do not matter much. You already have so much horsepower that the measurable difference is really slim.

As you can see, the result is a faster performing card, yet barely. The game you are looking at is Mass Effect with maximum in-game quality settings enabled. Everything is maxed out, no AA though (not supported in-game), the noise filter however is enabled. Please, don't over-do your tweaks though, and be careful as overclocking typically is not covered by the warranty.