HOWTO: Overclock C2Q (Quads) and C2D (Duals) - A Guide v1.1 - Overclockers Forums

Overclock 3d section.
Source: How To Overclock Your Graphics Card : Introduction - Review Tom's Hardware

Introduction

Overclocking is more popular than ever. And since it’s so easy to boost
the frequency of your Intel processor, it would be a shame not to. But
CPUs aren’t the only components that can be overclocked.
The GPUs on graphics cards can also be speeded up, and so can their
memory. And since an affordable card only differs from more expensive
ones in its clock speed, overclocking can be your key to some real
savings.



Overclocking a GPU is a less common process than
overclocking a CPU, and above all, it’s more complex. One of the
reasons for that is that a graphics card’s BIOS is not as easily
accessible as a motherboard’s. This article will shed some light on the
different methods that can be used and the results you can expect when
overclocking your graphics card.


Software or Hardware Overclocking?

It turns out that there are several ways to overclock your graphics
card. We’ll take a look at each one in turn. First of all, you should
know that you can overclock your card either temporarily, using Windows
software utilities, or permanently by flashing your BIOS. The Flexibility of Software




The first method is the best known. There are numerous utilities for AMD/ATI and
Their functions are often similar. The best ones let you set the
operating speed of the GPU and the memory, but also the cooling power,
and some let you load complete overclocking profiles and configurations
of 3D functions to suit the application you’ll use. In fact, these
utilities multiply the possibilities offered by the cards’ drivers.
This implies that the ForceWare or Catalyst drivers are not totally
ignorant of overclocking... And in fact, Nvidia and especially ATI are
emphasizing overclockability more and more, which has become a strong
sales argument. Software overclocking is very flexible to use
(generally all you do is slide the frequency cursors and click "OK"),
but it’s not free of drawbacks. It depends on a memory-resident program.
That program consumes a small part of system resources, and can crash.
The programs can contain bugs, or be incompatible with certain cards,
certain driver versions or certain operating systems. What’s more, each
time you re-boot the system you have to reconfigure everything. Under the Hood

In short, a more permanent, more robust solution would be preferable – as
with CPU overclocking, which won’t change unless you voluntarily modify
the motherboard’s BIOS. And in fact, it works the same way with a
graphics card. Permanent overclocking requires a change to the settings
that are "hard-wired" in the card’s own BIOS. But while all you need to
do to access your motherboard BIOS settings
is press F1, F2 or Del when your PC is booting, the graphics card’s
BIOS is not that easily accessible. You need a special utility to read
and edit settings and save the new version, which will then be written
to the card itself by flashing with yet another utility. Sound
complicated? It may be, but it’s not at all impossible. And we’re here
to tell you how to do it. Keep Cool and Spend Your Money




XFX GeForce 8800GT Alpha Dog

However, if all this scares you, you can always go with a factory overclocked
version, when the vendor does it for you. Models like this are
extremely common, since third-party graphics cards manufacturers have
found overclocking to be one way to set themselves apart from the
competition. Certain ones, like XFX, may even owe all their success to
the wide range of overclocked models they offer. But you should know
that most of the time, pre-overclocked cards make you pay a lot for the
few extra performance percentage points they offer. Test configuration


Our tests were run on our reference system with an Asus P5E3 motherboard,
an Intel QX6850 processor and 2 GB of Crucial DDR3. The operating
system installed was the 32-bit version of Windows Vista SP1. For each
card, we used the most recent versions of the drivers available at the
time of the test – that is, ForceWare 174.53 and Catalyst 8.3.