|PCStats Test System Specs:|
Intel Pentium 4 2.4C
12 x 300 MHz = 3.6 GHz
12 x 318 MHz = 3.82 GHz
340 MHz = 4.08 GHz
ATi Radeon 9800XT
2x 256MB Corsair XMS3500 CAS2
||20GB Western Digital 7200 RPM |
||NEC 52x CD-ROM|
||PC Power & Cooling Turbocool 510|
WindowsXP Build 2600
Intel INF 5.00.1012
*i875P Northbridge was
for all overclocking
While it's great to know the various forms of cooling available to
the enthusiast, today we're going to show you how they scale against each other. We'll be
focusing on a Pentium 4 platform but you should expect
similar results with an AthlonXP/Athlon64 based system as
Arctic Silver Ceramique thermal compound was used for all tests, and each test
configuration was allowed to sit for five days (per test) to allow the thermal
paste to cure before any the temperatures, or maximum overclocked
speeds were noted.
Ambient temperatures varied from 20-22 degrees
Celsius, and the CPU temperatures were taken with the Winbond Hardware
Monitor. This is certainly not the most accurate method of taking temperature
readings, but should be good enough for ball parking what to expect... After
all, overclocking isn't an exact science.
Cooling with Heatsinks and Fans - Air cooling
Heatsinks have come a long way from the
puny little things used on P133 class processors just a few years ago. Current
coolers have to cope with updwards of 100W heat loads, and many are now made with an
exotic blend of aluminum extrusions, copper, heatpipes, and radically advanced
The Impact of Airflow
Heatsinks for high performance processors are
designed to be used with forced-air cooling, which means they require fans.
The more air that passes along the fins of the heatsink, the better
the heatsink's ability to draw heat away from the processor and get rid of it.
So as a far as enthusiasts are concerned, the bigger and faster the fan (CFM),
The attraction of air cooling is that it doesn't require a large monetary
investment. A really nice overclockers heatsink will general costs less than $100CDN, which makes it
quite affordable compared to the $300-400 investment you would need to spend for a
decent watercooling setup.
For the following
overclocking tests with a heatsink, we used the Thermalright AX-478 heatsink equipped with an 80x80x38mm Vantec Tornado fan (which pushes
84 CFM of air). The AX-478 is a bit old, but
it's still easily one of the better heatsinks on the market. Team that thing up with a Vantec
Tornado and you've got yourself an impressive air cooled combo. Better put your ear
muffs on though....this configuration is in the 60-70 dBA noise range!
high end air cooling we were able to hit a maximum
speed of 3.6 GHz with a small voltage increase (1.6V) while maintaining 100% stability
in the benchmarks; Prime95, etc.
Raising the voltage past 1.6V did not help us overclock any
higher, and was actually detrimental in fact.
Temperatures were on the high side, but that
shouldn't be much of a surprise. The 2.4C Pentium 4 @ 3.6 GHz idled
at around 45 degrees Celsius, while load temps reached as high as 57 degrees Celsius! Despite
that, the processor ran quite well, it's just a shame the PC was louder than
a jackhammer in a rock concert!