Overclocking the three cards setup in SLI
Overclocking the three cards set up in SLI
As most of you know, with most videocards 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 simply 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 tools 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 some very nice built in options for you that can be found in the display driver properties. Based on Rivatuner you can alternatively use MSI AfterBurner which will work with 90% of the graphics cards out there. We can recommend it very much, download here.
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 than 5% on the core and memory clock. Example: If your card runs at 600 MHz (which is pretty common these days) then I suggest that you don't increase the frequency any higher than 30 to 50 MHz.
More advanced users often push the frequency 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 may 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 this was not really surprising, but as you can see, the card can overclock much MUCH higher and that has a very positive effect on overall performance. At default you'll easily lift the card over 800 MHz on the core.
| Original | This sample | Overclocked |
| Core Clock: 772MHz | Core Clock: 772MHz | Core Clock: 830MHz |
| Shader Clock: 1544MHz | Shader Clock:1544MHz | Shader Clock: 1670MHz |
| Memory Clock: 4000MHz | Memory Clock: 4000MHz | Memory Clock: 4400MHz |
Now with three cards we decided to do things relatively safely. We upped fan RPM control towards 85%.
Temps on one of the cards goes up to 85~90 degrees C on the GPU, that is still fine... but borderline. We quite honestly would not recommend any voltage tweaking at this point as you already have so much heat to dispose of. So let's have a look at some examples while overclocked.
Metro 2033, maxed out quality settings with AAA enabled.
When you have so much brute horsepower already, it really becomes difficult to show any real gains in performance with overclocking.
Battlefield Bad Company 2 maxed out quality settings as before with 8xAA 16xAF
Once again there's not much to look at. Overclocking does very little at this stage of performance. Now typically 3DMark Vantage is a title we show overclocked as well, but for whatever reason this was the one title that would not finish properly while being overclocked.
