Overview
This TekSpek explains why you'd want to overclock your graphics
board, the risks in doing so and how you can go about doing it.
Why?
Most of you reading this TekSpek will know that if your graphics
card is the limiting factor in your PC's games performance, that
making it run faster will give you more performance at your chosen
settings. Depending on the game and the rest of your PC's components
and their setup, there's a balance between being limited by the
graphics board and being limited by something else.
So if you're able to make your graphics card go faster than normal
then you'll get more performance, and for nothing other than your
time and effort. Board performances can almost always be adjusted
with software, which makes it very simple to do. Things to consider
when overclocking are simple (and somewhat obvious too), making
the whole process a doable one with little fuss. This TekSpek will
show you how.
Risks
The risks in overclocking are potentially fatal to the graphics
board, since they create more heat for the cooler to manage and
may also increase the voltage supply to the GPU and memory devices.
Running things out of specification therefore carries a risk, but
as long as limits are explored sensibly then permanent problems
or damage can almost always be avoided. However, be aware that improper
overclocking can have bad side effects and therefore you do so entirely
and absolutely at your own risk, not ours!
How to do it
We'll illustrate how it's done with RivaTuner, the very popular
tweak utility for NVIDIA (and some ATI) graphics cards, and your
author's NVIDIA GeForce 7800 GTX 512, however the basic techniques
and methods are applicable to almost any modern graphics board and
its associated overclocking tools. We'll present a list at the end
of this TekSpek.
When running RivaTuner for the first time you'll see the following,
which confirms what graphics board you have installed and its basic
configuration.
To access the overclocking tool inside of RivaTuner you click the
button next to "Customize..." alongside "ForceWare
detected". That gives you the flyout menu with access to the
button (first one) that'll bring up the overclocking tool.
Clicking the right button then shows you the following, where clocks
can be adjusted.
Ticking the "Enable driver-level hardware overclocking"
checkbox and the subsequent "Detect now" button to grab
the current clock rates lets you start adjusting them. Note the
current 550/850 (with the 850 shown at its effective clock rate
of 1700) clocks and the sliders for adjust.
Now the meat of the whole thing: adjusting the clocks incrementally
and testing things out. To find the reasonable limits of both core
and memory, you want to adjust both at the same time in reasonable
increments, setting those clocks and playing a game or running a
benchmark to test stability, monitoring heat output and what's on
the display to make sure things are alright for an extended period
of time.
We suggest 5 or 10MHz jumps, until things go wrong and the application
crashes, you get display corruption, the entire system hangs or
resets, or something else out of the ordinary. The small increments
and thorough testing for anomalies here means that things won't
break, just get unstable at a certain point. When that happens,
take the last known good clocks -- whatever they happen to be --
and start adjusting core and memory clocks individually in smaller
(1 or 2MHz) increments until you reach the absolute limits, testing
for good operation in your favourite game or strong stress test
such as 3DMark. If your chosen overclocking tool has a stability
or rendering artifacts test, you can use that in conjunction with
something a little more real world.
The act of small incremental increases and heavily stability testing
is the key to a successful overclock, and be sure and monitor temperatures
on your graphics card and system to make sure the extra heat output
of the faster switching transistors on GPU and memory devices.
Here we are 15MHz away from the base clocks on our test board,
just so you can see it in action.
Tools to help you overclock your graphics board
Here's a list of tools, drivers and their targets, to help you have
a go at overclocking your own board.
RivaTuner - Almost all NVIDIA and some ATI products
ATI Tray Tools - ATI graphics boards
ATI Tool - ATI graphics boards
Official ATI display drivers
Official NVIDIA drivers
3DChipset - Official and unofficial drivers repository for NVIDIA
and ATI
Summary
Overclocking your GPU is free and easy, and provided you take it
slow and test each incremental step thoroughly, free performance
should come at the expense of nothing more than a bit more heat,
and your time and effort of course. This TekSpek sought to explain
the hows and whys, and give you a list of tools to help you on your
way.
