Radeon HD 4890 review | test - 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's tested card anyway, but we'll still show it ;)

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

Now here's where things get even more interesting. The card seems to be a decent overclocker.

GPU clock frequencies:

• The reference clock for the card is 850 MHz, HIS clocks it at 900 for the OC model, we ended up at 971 MHz.
• The memory clock for the card is 3900 MHz (975x4), we ended up at 4600 MHz (=4x1150 MHz).

 I would not be surprised to see you guys yield even better results. Especially if you'd apply some extra cooling.

We used Rivatuner, here's what such an overclock will get you extra, performance wise:

* Brothers in Arms hells Highway

BIA: HH shows a very nice increase in performance once again. Mind you that we used the same settings as before, everything maxed out in-game.

With just the reference cooler we reached a clock frequency of nearly 1000 MHz on the GPU. That really is quite something. With this overclock we in fact reach GeForce GTX 285 performance levels.

* 3DMark Vantage

Hate it, love it... 3DMark Vantage also is showing a nice bump in it's score, you'll gain another ~1000+ points merely based on a graphics card overclock.

Please, don't over-do your tweaks though, and be careful as overclocking typically is not covered by product warranty.

Alright, enough numbers already. Let's head on over to the conclusion.