Advanced guide
Improve your
PC’s performance and stability with our BIOS tweaking guide.
There are many ways to get more
from your PC: tweak application settings, play around with Windows, update your
drivers – all these techniques have their place. But don’t forget the BIOS.
The configuration here plays a key part in setting up your hardware, and no
system will deliver its best possible performance without having a properly
optimised BIOS.
Directing you to the right
setting isn’t always easy. Every BIOS has its own menu structure and naming
conventions, so while we can point you in the right direction for a particular
option, ultimately you’ll have to browse for it yourself. And occasionally you
might not find an equivalent setting at all, but don’t worry, just move on to
the next: there are plenty of BIOS tweaks for everyone here.
Remember to be cautious when
tweaking your system. Make a note of the original settings so that it’s easy
to change back later. Try to modify only one or two values at a time, then test
your PC to make sure everything’s still working well. If an issue does emerge,
and you can’t get back into the BIOS setup program, then there’s an easy
fix: just clear the CMOS RAM and start again with default settings. Your
motherboard manual will tell you how to do this.
The typical BIOS set-up program
is launched by pressing a particular key when your system first boots – often
[Del] or [F2] – although a prompt should tell you what to use. The opening
menu is commonly called Standard CMOS Features, and contains two entries for
each of your IDE channels: IDE Channel 0 Master, IDE Channel 0 Slave, IDE
Channel 1 Master, and so on. Each entry is normally set to Auto, allowing your
PC to detect whether an IDE device is present, but if the channel isn’t being
used then you may also set it to None. Your PC will then skip the detection step
and boot a little faster.
The Advanced CMOS Features menu
generally defines your PC’s boot order, which by default will be something
like floppy; CD ROM; hard drive. Not only does checking floppy and optical
drives slow the boot process, but it’s also a security risk, because you’re
more likely to accidentally boot from virus-infected media. Change it now so
your hard drive comes top of the list.
Ironically, this Advanced menu
is also where you’ll usually find a particularly pointless legacy floppy
setting, Boot up floppy seek. The system uses this to find out if you’re using
a 40-track, 360KB floppy, and as we’d like to bet you’re not, is another
delay in your PCs boot time. Turn the setting off immediately.
Integrated peripherals
Modern motherboards are overloaded with ways for your PC to communicate with the
outside world and other devices, far more than you actually need. Is your PC’s
integrated network controller unused, because it’s a standalone machine? Maybe
you never plug anything into the parallel or serial ports, and your Firewire
(1394) controller is wasted because your devices are USB?
If any of this sounds familiar,
then work your way down the list and turn off whatever features aren’t
required for your PC. This is particularly important if you have integrated
graphics or sound, and have also installed a separate graphics or sound card,
because it’ll ensure you avoid conflicts between the two. But you’ll also
benefit because BIOS initialisation will be faster. It’ll be easier for your
system to allocate resources, and Windows may need to load one or two less
drivers, saving a little RAM.
Anyone who is still using the
parallel port, though, should check its mode here. By default it’s set to SPP
(Standard Parallel Port), the slowest option available. Experiment with EPP
(Extended Parallel Port) or ECP (Extended Capabilities Port) to see if either
offers you improved speeds.
Power management The Power
Management menu will contain a range of ‘Wake on’ functions, letting you
turn on your PC by moving the mouse, touching the keyboard, an incoming ring on
the modem – whatever your board supports. These functions might seem worth
trying if they avoid the need to scramble under the desk for your power button,
but they also increase the chance of turning on your system accidentally. It’s
generally less hassle to leave them turned off.
There is a real hidden star in
this menu, though, usually called something like ACPI Suspend Type or S3 Suspend
Type. This governs how your PC handles being switched to Standby. Leave it in
the default S1 setting, and it still uses a ludicrous amount of power: 182W when
on for our test PC, only dropped to 86W in standby mode – a lot when it looks
like the system is off.
Change your suspend type to S3,
though, and more devices will be switched off, while their status will be saved
internally. This should reduce standby power requirements by another 50 per
cent, perhaps more, saving you a bundle on PC running costs. The only potential
problem is that it may not work with older hardware, so you should experiment
first. If any component doesn’t restore properly from standby, restore the
previous S1 setting to get it working again.
CPU configuration
An AMI BIOS typically provides access to processor settings in the Advanced |
CPU Configuration menu, but other systems often place them in a general
overclocking screen, like Gigabyte’s “MB Intelligent Tweaker”. So don’t
be surprised if it takes a while to locate them.
The aim of these options is to
help you overclock your CPU and run it at a faster rate than is intended, which
can result in major performance gains. But at a price. Your PC may also become
more unstable, lock up unexpectedly or deliver more blue-screen errors. Faster
processors generate more heat, so you might need to install larger heatsinks.
And even then your system might have a shorter life.
Still here? We don’t have the
space to cover overclocking properly, but one very simple method involves
looking for the FSB Frequency setting, and increasing it by a few MHz. The FSB
speed governs both the speed of your CPU and memory, so you should see immediate
results. Make your increases gradual, perhaps two per cent of the initial FSB
value, then save the changes and test your PC thoroughly to ensure it’s
stable.
When you do push too far and
your PC starts to fail, switch the settings back to the last stable value, and
look for CPU and memory voltage levels. Increase these by the smallest possible
increment and you may be able to get better performance. But be careful: apply
too much voltage and you really can trash your hardware immediately. And extra
heat increases the change of failure later, too.
Memory settings
Browse around the CPU Settings screen and you’ll find options for your memory,
too. Most of these memory timing values relate to specific delays, defining a
period of time the CPU will wait to perform an operation. Reduce these delays
and you can achieve extra performance, perhaps five to ten per cent, but you
face the same risk as overclocking your CPU: a more unstable system. Only
continue if that’s a risk you’re willing to take.
It’s potentially dangerous,
but the overall process of memory optimisation is at least a simple one: you
pick a setting, reduce it, then test your PC for stability. If all is well,
reduce the timing again. Keep repeating the process until your system becomes
unstable: locks up, produces blue screen errors, whatever it might be. Then
restore the last stable value, and move on to the next. That’s the general
rule, but it doesn’t apply to everything. Here are the settings we recommend
you optimise first.
Command Rate: Also known as
Command Per Clock, this defines the delay between selecting a memory chip, and
sending it commands. Set to one clock cycle or “Disabled” for the best
performance.
CAS Latency Control (tCL):
Typical settings here are Auto, then values from 1 to 4.5 (lower is faster).
Change this value and you must also modify Min RAS Active Time (tRAS) (see
below).RAS to CAS Delay (tRCD): These values are usually Auto or 0 to 7: the
lower values offer the best performance here.
Row Precharge Time (tRP): This
defines the delay between successive accesses to the same memory bank. Again,
values are usually Auto or 0 to 7, and lower values are faster.
Min RAS Active Time (tRAS): This
value is generally calculated from two others. As a rule: tRAS = tCL + tRCD + 2.
If you change this, you must also change the Row Cycle Time (tRC) (see below).
Row Cycle Time (tRC): This is
the number of clock cycles it takes to activate and precharge a particular row
in memory. It should usually be calculated from other settings: tRC = tRAS + tRP.
Row Refresh Cycle Time (tRFC):
This is a key memory refresh figure. Possible values are usually Auto, or 9 to
24: lower values are best, usually two to four more than the Row Precharge Time
setting.
Write CAS Latency (tWCL): The
normal settings are Auto, or 1 to 8. Keep the values low (1 if you have DDR
memory, 2 if it’s DDR2) to improve write performance.
Bank interleaving: This setting
allows one bank of memory to be refreshed while another is being accessed,
improving efficiency. Turn this setting on, or at minimum set it to Auto for the
best results.
Rounding up the rest
These settings aren’t always found on the same menu, but if you discover any
of them in your BIOS then this is what we’d recommend you do. Remember though,
if you’re unsure or worried about making a change to your BIOS settings, note
down how the option was initially configured so you can return to it if your
machine becomes unstable. Finally, only make one change at a time, save it and
then test your PC. This way, if you do run into a problem you’ll be able cure
it quickly and with certainty.
Fast Boot: Also known as Quick
Power On Self Test, this option skips the basic memory test performed when your
PC starts. Enable it for a faster start time.
AGP Aperture Size: This defines
the address space available for AGP memory addresses and is also known as
Graphics Aperture. 64MB or 128MB are generally best, but as long as your system
is running at its rated AGP speed we’d leave this alone.
System BIOS Cacheable: Options
that refer to caching or “shadowing” ROMs may sound useful, but most perform
no function under Windows systems and should be disabled. The one possible
exception is “Video RAM Cacheable”. Enabling this feature on some boards may
turn on write combining, which is good for performance. Try that setting both
ways.
USB 2.0 Controller Mode: Don’t
be confused by the terminology. The correct setting for this is HiSpeed (480
MB/s), not FullSpeed (12 MB/s).
Spread Spectrum Modulation: This
is a technique that is sometimes used to reduce electromagnetic interference
from the AGP, PCI or PCI Express buses. It’s more likely to cause problems
than fix them though, so we’d suggest turning this off.
PCI Express Maximum Payload
Size: This defines the maximum amount of data that can be included in a PCI
Express packet. This should automatically be discovered by the system, but
increase it to the maximum anyway, just to be sure.