13 - Radeon series 4800 Overclocking

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.

Okay I used the overclocking results from the previous 4870/4850 article as we used these cards in that review as well. Okay, we took the game Mass Effect and the Radeon 4870. Check this out.

Radeon 4870 @ 790 core & 4400 MHz memory

As you can see, the result is again a faster performing card. 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.

You can expect to push another 5 to 10% additional performance out of the card, completely free. This will yield you some really good results. We got the core to 790 MHz and the GDDR5 memory up-to a crazy 4400 MHz. Which really is just a great overclock. Now you need to realize, we were restricted by the ATI catalyst software to overclock any further. Once we have Rivatuner up and running with these cards, I guarantee you you'll be able to take it even further.

But please, don't over-do your tweaks though, and be careful.

Overclocking results typically result into slightly more heat build-up in the GPU as well, but not with this cooler. Heavily stressed the core temperature remained at ~78 degrees C. Though pretty hot, still nothing to worry about here as the GPU can certainly take it, and thanks to the cooler heat is exhausted outside the PC.

That other card then ...

Radeon 4850 @ 700 MHz core and 2300 MHz memory

Let's fire up COD4 here and see if we can boost that framerate a little with an overclock as well.

Image Quality setting:

• 4x Anti Aliasing
• 16x anisotropic filtering
• All settings maxed out

Now please bare in mind that no 3rd party overclocking tool is ready just yet, so we had to overclock through ATI Control center. The core we could push to the maximum allowed 700 MHz, and we found a memory limit at 2300 MHz. That's actually a pretty significant overclock.

High temperatures or not, there's definitely room for a little more tweaking, and it's worth it to do so. Quite nice to see. Pretty much you just tickled GeForce 8800 Ultra performance wise right there.