Gigabyte Radeon HD 7970 OC WindForce review

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Overclocking the graphics card

 

Overclocking the graphics card

As most of you know, with most video cards 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 to 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 AfterBurner which will work with 90% of the graphics cards out there. We can really recommend it, 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, to not 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 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.

Original This sample Overclocked @ 1.25V
Core Clock: 925 MHz Core Clock: 1000 MHz Core Clock: 1238 MHz
Shader Clock: 925 MHz Shader Clock: 1000 MHz Shader Clock: 1238 MHz
Memory Clock: 5500 MHz Memory Clock: 5500 MHz Memory Clock: 6200 MHz

If you are not using voltage tweaking, please use the Catalyst control center as it will allow you to overclock the card really well.

Radeon HD 7970

Open up AMD overdrive. Now we need to free the card up from TDP restrictions first, so all the way down move the Power control settings slider towards 20%. The max allowed board TDP is 250 Watt x 1.20 = 300W of overclocking headroom.

Overclocking wise the card will allow itself to be clocked to roughly 1050~1100 MHz on the core easily (!) and that's without additional voltage tweaking. The CCC slider limitation however is 1200 MHz.

Should you be willing to voltage tweak (it is more dangerous as it creates much more heat inside the GPU) then we'd say 1200~1250 Mv should be your target for roughly 1200 MHz.

We applied  1250 Mv and ended at 1238 MHz with a stable overclock, and that is very nice. The GPU was getting slightly warmer as we reached 70 Degrees C but by compensating the additional heat, the cooler RPM went up and as such the noise level now has risen towards roughly 43~44 DBa.

None the less we have extra performance at our hands, have a peek at the results when overclocked.

Gigabyte R7970 OC

Above, Crysis 2, same maxed out image quality settings as before yet now with added overclock results:

  • DirectX 11
  • High Resolution Texture Pack
  • Ultra Quality settings
  • 4x AA
  • Level - Times Square (2 minute custom time demo)

Gigabyte R7970 OC
 

Above, 3DMark 11 - the Performance test and score. As you can see, there is an additional bump in this very GPU limited software, lovely.

Gigabyte R7970 OC

Above, Alien versus Predator, in 1920x1200 at 4xAA and 16X anisotropic filtering

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