SLI Scaling | Overclocking
SLI Scaling
With the nature of this dual-GPU beast we figured it's also interesting to show you a quick comparison to other multi-GPU setups and what will benefit you the most in what situation. Have a look at the following chart please:
Now you are looking at Crysis Warhead with the same IQ settings as before. So if you purchase 3x a GTX 285 and set them up in 3-way SLI then make no mistake .. that solution is much faster, that is until you hit 2560x1600 as the MARS will kick in there with extra memory available.
Compared to a GTX 285 in 2-way SLI you'll notice 100% similar performance, which makes sense (expect 25x16 again due to extra memory).
So here's the weird conclusion you can draw from it, 3-way SLI GeForce GTX 285 is not only cheaper .. overall is a good amount faster as well.
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.
We used Rivatuner 2.24, our end results:
Above you can see the overclocked results for Crysis WarHEAD, same image quality settings as before, in DX10 mode. Blue is the default test session we showed you, the lower light blue line is showing standard GTX 285 performance for scaling purposes and then in red the overclocked results.
| Original NVIDIA clocks 285 | Vendor clocks | Overclock with Rivatuner |
| Core Clock: 675MHz | Core Clock: 675MHz | Core Clock: 704MHz |
| Shader Clock: 1476MHz | Shader Clock: 1476MHz | Shader Clock: 1603MHz |
| Memory Clock: 1253MHz | Memory Clock: 1152MHz | Memory Clock: 1251MHz |
So we could not push the card much further really as we'd run into temperature issues.
We used Rivatuner 2.24b, the latest update is compatible with the current GeForce driver 190.38 WHQL driver.
