44 MA XIMUMPC NOVEMBER 2004
Build It!
Step 19 : Last minute housecleaning
It’s exciting when you’ve installed the last
piece of hardware, but you’re not totally
done with construction until you’ve done
a thorough double-check. You need to
ensure that each component that requires
power is connected to the power supply
(a) , that all your fans have power, and that
your cables are tidy (b) —tucking them out
of sight will not only make the interior of
your machine more attractive, it will also
improve airflow and thus cooling in your
case! Get this right now, and you’ll make
life a lot easier on yourself.a
b
ADJUST YOUR
CAS LATENCY
Manually tweaking
your memory set-
tings can yield big
performance gains.
The memory tim-
ing menu is usu-
ally located in the
Advanced Chipset
screen or a sub-
menu of this screen.
Before you can
adjust the memory
timing, you must
change the set-
ting for “Configure
SDRAM Timing”
from the default of
SPD to User (a). SPD
uses the settings
built into a chip on the memory
modules to determine the memory
timings. User lets you select your
own timings. If you need to deter-
mine the standard timing values for
your memory modules and the infor-
mation isn’t available in the BIOS,
check the memory vendor’s web site
for the modules’ data sheet.
Memory speeds are described
in two different ways: frequency
(measured in MHz) and latency(how quickly the module can send
data after receiving a request). DDR
SDRAM is available with CAS laten-
cy values of 2.5 and 2.
To improve performance, try
using a lower latency value. For
example, if your memory has a CAS
latency value of 2.5, try 2 instead. If
the system won’t run properly, go
back to the default CAS latency and
try other adjustments.Even the smallest changes to the BIOS can have a big effect. Here are our two
favorite BIOS tips. Keep in mind that each BIOS is a little different, so you may
need to dig around in your BIOS to find the appropriate settings.How to Tweak Your BIOS for Performance
and ReliabilityADJUST YOUR MEMORY TIMING
Depending on the BIOS your system
uses, you can also adjust other memo-
ry timing factors, such as Row pre-
charge time, RAS pulse width, and
RAS-to-CAS delay (b). Row pre-
charge time (also referred to as
tRP) refers to the amount of time
needed (in clock cycles) to acti-
vate the memory bank. RAS
pulse width (tRAS) refers to the
amount of time (in clock cycles)
to leave the row of memory open
for data transfers. RAS-to-CAS
delay (tRCD) refers to the
amount of time needed to switch
to a different row of memory to
access data not found in the cur-
rent row. For maximum speed,
these should be set as fast aspossible (smaller values are faster).
Try changing one setting at a time,
and testing the stability with a memory
benchmark like Memtest86
(www.memtest86.com).a
b