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 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 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. 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 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.
Official Overclocking
Above you can see the overclocked results for Resident Evil 5, same image quality settings as before, in DX10 mode. Blue is the default test session we showed you, and then in red the overclocked results.
| Original | This sample | Overclocked |
| Core Clock: 850MHz | Core Clock: 900MHz | Core Clock: 975MHz |
| Shader Clock: 850MHz | Shader Clock: 900MHz | Shader Clock: 975MHz |
| Memory Clock: 4800MHz | Memory Clock: 4800MHz | Memory Clock: 5488MHz |
As you can see, the R5870 Lightning can overclock higher, now we where hoping to pass 1 GHz, as that is some sort of personal goal I had. Unfortunately our sample could not pass 1000 MHz without running into problems. We fired off extra cooling, voltage changes, still not possible.
Still we squeezed a good 975 MHz stable out of the GPU core and the memory was clocking really well at close to 5500 MHz.
Unofficial Overclocking tweak tip
This is a generic note for ATI based overclocks. For most reference cards ATI defines a maximum allowed clock in the BIOS and signs that area with digital key. If you run into such a limitation then be aware of a tweak for MSI Afterburner. Now let me clearly state that MSI does not support this feature officially.
Here's what you do. Once you install, MSI AfterBurner just edit the AfterBurner.cfg file located in the installation directory. Here we can now bypass the clock frequency limits set by ATI. In the .cfg file seek EnableUnofficialOverclocking and set it to 1
Now here's the thing. By enforcing this tweak you will loose PowerPlay, that could open a new can of worms (because ATI doesn't really support these undocumented overclocking interfaces), there can be different (negative) side effects. Your call to make, if you run into problems... it's not Afterburner causing it, so please do not complain.
