Overclocking a Graphics Card
The practice of overclocking a graphics card has become commonplace within the PC enthusiast world. Overclocking a graphics card increases performance and it’s a simple process to do. It involves increasing the core and memory clocks of your graphics card, making it run faster than was originally intended. Although overclocking is a good idea in many cases, there are some precautions that must be taken in order to do it safely.
DISCLAIMER: The advice and guide given in this article comes from my own personal experience. Overclock your graphics card(s) at your own risk, we take no responsibility for the damage of computer parts.
The first thing you need to do in order to overclock a graphics card is download an overclocking utility. MSI Afterburner is a good choice, but EVGA’s Precision-X and Sapphire’s TriXX also work well.
MSI Afterburner- http://www.majorgeeks.com/mg/getmirror/msi_afterburner,1.html
Start by increasing the power limit as high as possible. This will ensure that your graphics card is getting enough power to run an overclock. Ensure that your power supply has enough headroom to run an overclocked graphics card. Take a look at your cards required power, and then increase it based on the increase in the power limit. For example, a GTX 970 requires 145 Watts. If I increase the power limit to 112%, the card will need an extra 17 watts to run.
Once you have increased the power limit, start increasing the core clock by 10MHz at a time. When you have a stable core clock move onto the memory clock, increasing it in the same way.
When overclocking you need to stress test the graphics card to ensure that it is stable. Stress testing also allows you to check the maximum temperatures of your graphics card and make sure that it is not overheating.
To stress test we will run two tests. Firstly, the 3D Mark Firestrike. You can find the demo here:
This benchmark stresses your graphics card in the same way which games do, and is the best method of testing the stability of your overclock. When running the benchmark check for artifacting and graphical glitches, which will indicate that your overclock is unstable. If this is the case you can either decrease your clocks and run the test again, or increase the voltage. Run 3D Mark Firestrike 2 times in a row (for each 10MHz increase), making sure that there isn’t any glitching. Once you see artifacting, decrease the core clock. When you are happy with your results, run Firestrike 5 times in a row to ensure that your GPU is stable. If the benchmark is successful, move onto the second test.
The second test requires you to run any demanding game for a lengthy amount of time. Only run this test once you achieved stability in Firestrike, as it will take too long to test a game on each 10MHz increase. Crysis 3 and Battlefield 4 work well as stress test. Warframe and Planetside 2 are good free to play titles if you don’t have any graphically intensive games in your library. If you can run a game for 2 hours straight you can consider your overclock stable.
Increasing the voltage to your graphics card can unlock the potential for huge overclocks, however there are caveats to this. Firstly, you will see temperatures rise as you increase the voltage. Rising temperatures can lead to thermal throttling, where the card downclocks automatically due to extreme temperatures. Increasing the voltage will also void the warranty on many cards, it’s always best to check your manufacturer warranty before venturing into voltage tweaking.
If you do decide to increase the voltage, increase it in 10Mv increments and stress test until the artifacting has disappeared. Make sure to monitor your temperatures whilst you do so.
Graphics cards can withstand surprisingly high temperatures, much more so than processors can. AMD states that 95 degrees is a perfectly safe temperature for their graphics cards, if they go past 95 degrees the cards will thermal throttle in order to keep the temperatures safe. Nvidia states that their maximum is around 90 degrees, meaning that both AMD cards and Nvidia cards can run very hot but still be considered safe.
If you find your graphics card is thermal throttling, you can do two things. Firstly, you can increase the fan speed of the card. This will cool things down significantly; however, it will increase the noise levels of your PC. Secondly you can decrease the overclock on the card. Core and memory clocks do not have much of an effect on temperatures, however an increased voltage can cause temperatures to skyrocket. Also bear in mind that a hotter running graphics card will lead to an increase in overall case temperature. This can cause problems for those with air cooled CPUs, as they rely on cool case air to work optimally.
Overclocking your graphics card is a great way to get extra performance out of your PC. All you need is an hour or so, and with that hour you can improve your PC’s performance greatly. When overclocking, make sure that your temperatures are within the safe limits, and that you are aware of the extra power consumption and potential voiding of warranties.