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. Typically you can tweak on core clock frequencies and voltages.
What Do We Need?
One of the best tools for overclocking Nvidia and AMD 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 can really 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 25 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.
All in all... tweaking GPUs is at your own risk!
| Original GTX 980 | This sample | Overclocked |
| Core Clock: 1126 MHz | Core Clock: 1203 MHz | Core Clock 1353 MHz |
| Boost Clock: 1216 MHz | Boost Clock: 1304 MHz | Boost Clock: ~1516MHz |
| Memory Clock: 7000 MHz | Memory Clock: 7200 MHz | Memory Clock: 8000 MHz |
With AfterBurner we applied:
- Temp Target 80 Degrees C
- GPU clock +150 MHz
- Power limiter 125%
- Mem clock +400 MHz
- Volatge + 87Mv
- FAN RPM 65% (slightly audible)
The boost clock will now render at over 1500 MHz, depending on the power and temperature signature. The GPU will continuously be dynamically altered on voltage and clock frequency to match the power and temperature targets versus the increased core clock. The Samsung GDDR5 memory used can run at almost 8 GHz (effective data-rate).
For all overclocked games above we have used the very same image quality settings as shown before. Overall the generic rule of thumb here for a decent tweak and overclock is that performance can gain anywhere from 5 to 20% performance. The end result depends on a lot of variables though, including power limiters, temperature limiters, fill-rate and so on, the performance increment can differ per card, brand, heck... even cooling solution and your chassis airflow.
When we take new thermal readings we see that in an overclock state with heavy GPU load and increased voltages these factors do have an adverse impact on the graphics card. GPU temperatures now hovers at ~70 Degrees C, the VRM area rises towards 85~90 Degrees when overclocked with added voltage.
Since we added extra airflow by increasing the fan RPM to 65%, we get better results opposed to reference. So you can play around with that a little yourself. Below the cooling performance in an overclocked condition shown in a thermal image.
