# How To Assemble A Desktop PC/Overclocking

Overclocking is the practice of making a
component run at a higher clock speed than the manufacturer\'s
specification. The idea is to increase performance for free or to exceed
current performance limits, but this may come at the cost of stability.

Extensive overclocking will result in the destruction of hardware so
ensure proper cooling before overclocking.

Overclocking is like souping up a car: if you just want to get where
you\'re going, there\'s no need for it. But it is fun and educational
and can get you a machine that provides performance all out of
proportion to its cost.

Think of the 4 GHz on your new 4 GHz Core i7 as a speed limit asking to
be broken. Some other components in your computer can also be
overclocked, including RAM and your video card in many cases. Over
clocking is possible because of the way electronic parts, especially
VLSI (Very Large Scale Integration) chips are made and sold. All
processors in a given line, the i7 for example, are made the same way,
on a large die that is cut up into individual processors, those
processors are then tested and graded as to speed, the best chips will
be marked as 4 GHz, the second best 3.8 etc. As time goes by and
production processes and masks improve, even the lower rated chips may
be capable of faster speeds, especially if vigorous cooling is
implemented. Also many manufacturers will mark chips that test faster at
slower speeds if there is higher demand for the lower end component.

It's important to note that not every chip will be overclockable; it's
really the luck of the draw. Some companies that sell 'factory
overclocked' systems engage in a practice called "binning" where they
buy a number of processors, test them for overclocking potential and
throw the ones that don't overclock in a bin to be resold at their rated
speed. Even with processors that have a reputation for overclocking
well, some parts simply will not exceed their rating.

That said, effective cooling can give a boost to a chip\'s
overclockability. With luck you will be able to get extra performance
out of your components for free. With luck and skill you can get
performance that is not possible even when using the top of the line
components. Sometimes you can buy cheaper parts, and then OC them to the
clock speed of the higher end component, though the cost of extra
cooling can compromise any money you may be saving on the part, not to
mention warranty and part life issues.

## Things that can\'t be overclocked

Although it is possible to overclock many of the components of a
computer (such as the CPU, memory and video card), it is not possible to
overclock all components. In particular mechanical components do not use
a clock speed and can not be overclocked. For example, it is not
possible to overclock a hard disk drive, a fan, or an optical drive such
as a Blu-Ray drive. For such devices other solutions exist, i.a. use a
quicker file system and/or faster components in the first place; also in
some special cases of hard disks drives, update the driver (which
contains optimized code); remap blocks with high latencies to low
latency blocks (using a tool such as mhdd), and in event a RAID is
present, change the configuration, driver and/or software and/or
settings. However such techniques and procedures are beyond the scope of
this document.

## Components

### CPU

#### Choosing the CPU

While the CPU is usually the best component to overclock, most CPU\'s
these days are locked, which means that the multiplier cannot be changed
from its default clocks. While previously (until Sandy Bridge), users
used to work around this limitation by adjusting the base clock of the
CPU, on Sandy Bridge till Broadwell (2^nd^ to 5^th^), attempting to do
so over a few megahertz would usually cause the system to crash, even if
the CPU itself is stable. This is because increasing the base clock
would also affect other system components.

This means that, at a best case scenario of a 5 MHz increase over the
usual 100 MHz base clock, an i3-4370 (3.8 GHz) can only be overclocked
by 38\*5 = 190 MHz, which would increase the clock speed to only 3.99
GHz.

This limits your Intel CPU choice to the following, if you want to
overclock:

1.  CPU\'s labelled with a K at the end of their model number (eg:-
    i5-13600K)
2.  Extreme Edition processors (X series). An example would be the
    12-core i9-10920X.
3.  Pentium G3258 (more on that later)
4.  C (high end graphics) line.

Most (if not all) AMD Ryzen CPU are overclockable; it is *not* necessary
to buy the highest-end model (aka the X variant) solely for
overclocking, though such variants may include better coolers instead.

For Intel chips, these overclockable chips usually come at a 5-15%
premium over the non overclockable but otherwise identical CPU.

Now about the Intel Pentium G3258. This chip caused a lot of hype when
it was first released back in 2014, as it was the cheapest and
lowest-end Pentium chip released by Intel in honour of its 20th year
anniversary. However, the main steal in this is the fact that this CPU
is highly overclockable, which made all the difference. Still though, it
won\'t reach the level of a stock i5 with overclocking; its dual-core no
hyperthreading design can hurt it badly, and it\'s now over {{#expr:
 - 2014}} years old. If you really need to
build an ultra-budget PC, then a Ryzen 3 or a non-overclockable Pentium
Gold processor would be a better choice.

The integrated graphics (if present) on the chip can often be
overclocked even on otherwise non-overclockable CPU\'s.

#### How to overclock

For older computers, one changes the clock speed of the CPU in the BIOS.
This holds true for newer computers as well, but you can usually use
Intel\'s Extreme Tuning
Utility
(XTU) or AMD\'s Wattman if you want to do it in Windows itself. This
method, while probably safer, is not the best method to overclock.

Assuming that you have a multiplier-unlocked CPU, head on to the BIOS,
look for a CPU-modifying option within the BIOS (it depends between
manufacturers), and raise the All-Core multiplier by a notch(For
example, if you have a 3.5 GHz chip with a multiplier of 35x, raise it
to 36x).

Then boot back into Windows and then run a stress tool like
Prime95. It is a good idea to run it for
some time (like an hour) but not for too long as you may end up damaging
your CPU instead. Keep a watchful eye at the CPU temperatures; you
should not go over 85C. If you do, you may need a better CPU cooler. Do
NOT use the stock cooler if you are overclocking!

If it passes, go back into the BIOS and increase the multiplier again by
a notch. If it fails, return back to the BIOS and then raise the CPU
voltage slightly. Then repeat the stress test.

Continue this process till

1.  The stress test has failed and you\'ve applied enough voltage, or
2.  The CPU is running too hot.
3.  The CPU is throttling (reducing speeds)

It is important that you do not apply too much CPU voltage as you may
end up damaging the CPU. Also remember to keep any adaptive voltage
settings on, as they reduce the voltage and prolong the life of your CPU
when it is in idle.

### Video card

Two different parts of a video card may be overclocked[^1], the GPU
(Graphics Processing Unit) and the RAM. In addition, disabled pipelines
on a video card may also be enabled through third-party drivers,
third-party software, or direct hardware modifications depending on your
video card type. Overclocking a video card is usually done through
third-party or proprietary software.

Recent AMD proprietary Catalyst drivers feature an interface called
Overdrive that allows for dynamic GPU frequency scaling based on its
temperature and load. Increase the load, the clock rate increases for
performance, but it\'s balanced against the increasing temperature.
Sufficient for simple increases in overall performance, this doesn\'t
allow for the best performance increase which requires overclocking the
memory. For that you\'ll need third-party applications or drivers.

An application example is ATITool. This program has many options,
including GPU and memory overclocking, temperature monitoring, and fan
control, allowing for a much more complete solution to overclocking ATI
based video cards. There are many third party drivers, omegadrivers.net,
for example hosts ATI and nVidia drivers as well. Both of which include
integrated overclocking and many unlocked features, including enhanced
image quality for nVidia-based cards.

nVidia users can use one of the many overclocking tools like MSI
Afterburner to overclock their GPU. Many of them also include
stress-testing tools built-in to validate the stability of the
overclock.

For Intel integrated graphics, one can overclock using Intel\'s Extreme
Tuning Utility, in much the same way as one would overclock the
processor.

The most important thing to remember about overclocking a video card is
cooling. This can\'t be stressed enough. Just as a CPU can be damaged or
have a shortened lifespan by overclocking or excessive and prolonged
heat, so can a video card. In the past year many inexpensive and easy to
install options have surfaced for cooling a video card, from adhesive
ram heatsinks which attach to un-cooled ram chips, to rather expensive
water-cooling solutions. A good midpoint (both in cost and
effectiveness) solution is to purchase and install a direct exhaust,
\"sandwich\" cooling solution. Direct exhaust means all air from the
cooling fan is blown across the video card and directly out of the
computer case, usually using the open PCI slot below the AGP (or PCIe)
slot. This allows for substantially lower GPU temperatures.

A sandwich cooler is two aluminum or copper heatsinks, shape formed for
a particular video card, that \"sandwiches\" the video card in between
the two and are usually connected by some kind of copper heat pipe which
allows for the hotter side to convey heat to the cooler side for
dissipation. The GPU should never surpass 80 degrees Celsius for optimal
performance and to avoid damaging the card. Most of the latest video
cards are rated to go up to 90 C, but this is NOT recommended by anyone.
The optimal temperature for a video card is 55 - 70 C for the card
itself (the GPU\'s temperature differs depending on which you have,) but
the lower you can get it, the better.

It is also possible to use software to change the fan speed on certain
cards. Changing the fan to run at full speed can cool the card better,
dependening on your card and the speed of the fan in the first place.
Software such as Rivatuner can be used for
Nvidia based cards.

## Getting the few extra MHz out of a chip

!Some people treat overclocking as a sort of sport, and try to get
ludicrous performance out of parts. While using liquid nitrogen for
cooling is fun, it\'s not very practical for day to day
use.

### Cooling

When increasing the speed of any computer components you are making the
components work harder and by doing so they output more heat. Heat can
cause system instability so cooling is necessary to help keep your
components stable at higher speeds. Without good cooling you could harm
or shorten the life of your system. CPU temperature can usually be
checked from within the BIOS. However, these are inaccurate as your CPU
is under almost no load in the bios. SiSoftware Sandra may be used
within Windows to check temperature. This should be done when your CPU
has been under a heavy load for a while for optimum results.

There are three types of cooling that are generally accepted for
overclocking: Air, water and peltier.

With both air cooling and water cooling some type of transfer material
is needed to move the energy away from the sensitive electronics. The
device used for this purpose is a heatsink. The two most popular
heatsink materials are Aluminum and Copper. The heatsink that is stock
on factory computers by major manufacturers (Dell, HP, Acer, Etc) is
usually made of aluminum, which has satisfactory heat transfer
characteristics. However when overclocking more heat is being produced
from the increase in power consumption. In order to obtain lower
temperatures a material with better heat transfer properties is
important and copper is the material that offers the best ratio of
price/performance.

### Power

Chips at higher speeds may need more power. Raising the vcore voltage on
a CPU might enable it to go at slightly faster speeds but by doing so
you add a lot more heat output from the CPU. The V~core~ of a processor
is the voltage at which a chip is set to run at with the stock speed.
This voltage may need to be changed when the multiplier is raised
because otherwise the transistors in the chip won\'t switch fast
enough - transistors switch faster the higher the supply voltage. If
there is not enough voltage then the chip will become unstable and crash
randomly. Good cooling is needed to keep the system stable at higher
speeds. Raising the vcore too much may harm or shorten the life of your
system. Raising the vcore can also greatly affect the stability of the
system. This is where a high quality PSU will come into play. While many
cheap, no-name brand PSU\'s will crash and die with more V~core~, a good
quality one will live to serve you for a long time. For most modern
Intel and AMD processors, it is strongly recommended not to exceed 1.45V
on the vcore, however even 1.45V can significantly reduce the lifetime
of a CPU.

Note: increasing the speed via multiplier without changing the voltage
will also increase heat output, but not as much as when also increasing
voltage. Having said that, increasing the multiplier without adjusting
the voltage may make your system unstable (undervolt).

## Undervolting

![](ThrottleStop_undervolt.png "ThrottleStop_undervolt.png"){width="800"}

The above screenshot shows the process of undervolting in ThrottleStop -
click (1) and adjust (2). -50 mV to -100 mV is around the tolerance
range of most laptops.

Instead of raising V~core~ during overclocking, you could also simply
*reduce* V~core~ and stay at stock clock speed. This is possible because
modern CPU\'s are ususually set at a voltage above the voltage it really
requires so as to account for manufacturing variances. The advantage to
undervolting include

1.  Lower heat output and power consumption
2.  Potentially higher performance (since the CPU can boost for a longer
    period and will hit the TDP limit less often)
3.  It works with any CPU; an overclockable CPU is not required.

Laptops can benefit the most from undervolting; their thin chassis means
that power and temperatures play a greater role than in a desktop.

Similar to overclocking, one can undervolt the CPU using tools like
Intel Extreme Tuning Utility, ThrottleStop or in the BIOS. For Ryzen
Mobile CPUs, an open-source tool AATU (AMD APU Tuning Utility) can be
downloaded
here,
which would especially help if your laptop is throttling due to STAPM
(skin temperature) issues.

Remember that just like when overclocking, you should start slowly and
also test the stability of the CPU undervolt (eg: by running Prime95).

## References

```{=html}
<references />
```
## External links

-   Introduction to Overclocking Guide for
    Beginners
    by Vito Cassisi
-   Overclocking the NVIDIA GeForce Video
    Card
    by Olin Coles
-   PC Performance
    Tips
    Mostly Video Guides To Speeding Up And Overclocking Your PC.
-   BIOS settings
-   Book on BIOS optimization for
    PCs
-   Overclocking guide for Centrino
    notebooks
-   BlazingPC.com
-   3 methods to Overclocking Your
    Computer
-   How to Lower Temperatures, Stop Throttling, and Increase Battery
    Life: The ThrottleStop
    Guide


[^1]:
    