32 MA XIMUMPC MARCH 2006 MARCH 2006 MA XIMUMPC 33
The Vapochill Lightspeed is the ultimate CPU cooler, and uses a refrigerant code-
named R507. It allowed us to ratchet the CPU clock speed another 650MHz (up to
5.04GHz) above what we were able to achieve with water, while keeping the CPU
at a cool 0 C, even under 100 percent load.WHAT IS VAPOR PHASE-CHANGE?
Phase-change occurs when a liquid changes to a gas, or vice
versa. Most liquids must absorb a ton of energy (usually in the
form of heat) before they’ll change phase, and they must expel an
equal amount of energy to convert back from a gas to a liquid.
Overclockers can utilize phase-change to transfer a ton of
energy away from a hot CPU to a more suitable location—like
a radiator. Cool refrigerant enters the CPU block, where it’s
warmed by the CPU until it enters the gaseous state, pulling
heat from the hot CPU in the process. This is the fi rst phase
change. Then the gas enters the compressor, where the pres-
sure of the gas is increased dramatically. Increasing the pressure
decreases the amount of energy that must be removed from thegas before it can convert back to liquid.
Next, the highly compressed gas is fed into the condenser,
which is a radiator/fan assembly. In the condenser, the gas cools
until it’s turned into liquid, changing phase for the second time.
Next, the liquid is squeezed into a thin, copper tube called a
capillary tube. At the end of the capillary tube is the cold plate
that rests on the CPU. This tube separates the high-pressure
section of the system from the low-pressure section of the sys-
tem. When the refrigerant returns to the CPU block—also called
the evaporator—the low pressure of that portion of the loop
lowers the energy required for the liquid to change phases once
more—from a liquid to a gas. Then the cycle repeats.STOCK AIR WATER PHASE-CHANGEBENCHMARKS
CLOCK SPEED ACHIEVED '(Z '(Z '(Z 5.04GHz
3DMARK05 OVERALL 8106
3DMARK05 CPU 9247
NERO 7 RECODE 911 7oUld not rUn
DVD SHRINK TRANSCODE 1459 VAPOR PHASE-CHANGE
In the cooling world, vapor phase-change is
the end-all, be-all of cooling. It gets a CPU
colder than a well-digger’s ass—sub-zero
usually. To see what phase-change could do
with our trusty Pentium Extreme Edition, we
ordered up a phase-change monster—the
Vapochill Lightspeed. As a stand-alone unit, it
can be integrated into any case and is perfect
for our testing.
Once up and running, the cooler ran
at negative 40 C at idle, and under load it
cranked a still-frigid 0 C. Though the $
price tag is tough to swallow, we have to
admit the performance is breathtaking.
With the Vapochill installed, we were able
to crank our CPU up 650MHz beyond the
previous high point, all the way to 5.04GHz.
And as the benchmarks show, this increase
in clock speed proved measurable gains in
every benchmark except DVD Shrink. We’re
not sure what happened there, but our DVD
encode test got slower at 5GHz. Regardless,
the proof is in the pudding, and gaining a
1.6GHz overclock that runs at 0 C under load
is damn impressive.Best scores are bolded.FINAL THOUGHTS
If you take a gander at the benchmark chart, you’ll see our over-
clocking results improved when we applied more cooling power to
the processor. This is a typical scenario. If you think you are at an
overclock ceiling, add a little more voltage fi rst, and if that doesn’t
work, add more cooling until you’re happy with your performance,
or until you hit your budget’s ceiling.
Remember, overclocking starts with the motherboard. It doesn’t
matter how much cooling you have, or what CPU you’re using—if
you’re mobo doesn’t have overclocking options, faghettaboutit.