PC enthusiasts have long relied on overclocking their components in order to extend the time their hardware stays potent enough. However, the processes seemed too risky and complicated for the layman to attempt. That has now changed over the years, and the process of overclocking, especially for Graphics Cards, has become extremely simple. So much so that it only takes a couple of clicks and minutes.

In this tutorial, we’re going to teach you how to overclock your graphics card. In case you’re wondering how to get some extra juice out of your card, you’ve come to the right place.

Why is Overclocking possible?
However, before we start with that, we need to understand why graphics cards are overclockable in the first place. The obvious question here is, wouldn’t manufacturers clock them to the maximum possible level by default, so they extract the most performance from them? The answer to that is no, because of a couple of extremely simple reasons.

Yield being one of them. Manufacturing chipsets is no easy task, and requires lots of precision. It’s also dependant on a lot of other factors, such as the quality of the raw materials, etc. So it’s highly unlikely that two chipsets will ever be the exact same – in fact it’s almost practically impossible.

So what do manufacturers do? Through extensive testing, they decide on clock speeds where they can keep the maximum amount of the chipsets they produce working properly. Of course, the speeds can’t end up being too low, either, lest they sacrifice too much on performance.

What that means is that every graphics card in the world is overclockable, but just how much leeway you have depends on the quality of your card. You could end up with a sample that hardly overclocks, or one that gives you a 20 per cent increase in clock speeds. It’s all in the luck of the draw, and there is absolutely no way of telling if the graphics card you’re buying is a good piece, or not. Unless you purchase one of the factory overclocked cards, but those are usually priced at a premium for the performance boost they give you.

The Actual Process
The process of overclocking a graphics card has become extremely simple these days, what with manufacturers releasing overclocking utilities for use with their cards. The good news here is that these utilities end up working with most other cards, as well. For this tutorial, I’ll be using MSI Afterburner to overclock the ASUS GeForce GTX 580 DirectCU II.



Test Rig:

  • Processor: Intel Core i7-2600K CPU @ 3.40 GHz
  • Motherboard: GIGABYTE P67A-UD3R
  • Memory: Corsair Dominator GT 4 GB DDR3 (2 x 2 GB)
  • Hard drive: WD Velociraptor  300 GB
  • GPU: ASUS GeForce GTX 580 DirectCU II
  • PSU: Cooler Master 1000W
  • Forceware 266.58

Before you begin, make sure you get GPU-Z, so you can check if your overclocks are actually being applied. Also prepare a benchmark utility, like a game or synthetic benchmarks like Unigine Heaven, which will tax your graphics card and help you figure out if the overclock is stable.

Now for NVIDIA cards, there are three adjustable clock speeds – those being the Core, Shader and Memory clocks. The Core and Shader clocks are usually linked to each other (with the Shader clock being 2x the Core clock), unless you have a really old card. Afterburner, by default, has these values linked and will maintain the ratio itself. These two clocks are what we’ll start with.

Do NOT, under any situation, go for a drastic increase in clock right off the bat. Go higher in increments – let’s say 20MHz at a time – and then use the benchmark and test if your card is running stable, while keeping an eye on the operating temperature. If it is running stable, you can increase the clock speed by the same number again. Rinse and repeat until you start seeing artifacts (flickery textures or coloured dots) on the screen, or if your card crashes. Once you reach that point, go back to the last stable overclock and leave it there.

Repeat the process, but with the Memory clock this time. Artifacts resulting from the Memory Clock being too high usually end up in a different colour than they’re intended to be. Also, most cards these days have the fan speed set on auto, which reacts to the operating temperature and in turn increases or decreases fan speed accordingly. While overclocking though, it’s wise to set a constant, and high enough, fan speed so the temperatures don’t go out of hand.



This is what we clocked the GTX 580 to, and even though the card had a bit more headroom, we decided to settle down here because it gave us a decent enough improvement in performance. For example, this card on stock benched at 80.3fps in Just Cause 2 at Max settings, 8xCSAA and 16xAF. Following the overclock, it gave us a healthy increase to 92fps. Keep in mind, this is a very moderate overclock.

Overclocking ATi/AMD cards:
The process for overclocking ATi or AMD cards is nearly the same as the one for NVIDIA cards, except the Radeons have one single processing clock, instead of NVIDIA’s divided Core and Shader clocks.

Upping the Voltage
Once you hit the effective ceiling for your graphics card’s overclock, you could go even higher by increasing the voltage level for your card, in turn increasing the amount of power your card receives. However, this reduces your card’s life span, makes it run hotter and therefore (because you’ll have to increase your fan speed so your card doesn’t burn out) noisier. I wouldn’t recommend doing it, but if you’re really feeling adventurous, most of the overclocking software include ways to increase the voltage levels. In case, Afterburner doesn’t work for you, get the software your card’s manufacturer provides and try it out.

So there it is, the beginner’s guide to overclocking your graphics card. Try it out, and let us know your results. Be warned though, that you have to be extremely careful doing this because it could end up frying your card, and most manufacturers consider overclocks as warranty voiders.

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