There are 4 parts to this
review, please use the pulldown below to browse sections or simply hit "Next"
at the bottom of each section to continue
 Testing
Brings Changes
This rig used to top out at 55 degrees Centigrade with air-cooling. The numbers
I'm quoting are from Motherboard Monitor 5 when stressing the processors with
3Dmark 2001 SE. Back then she was cooled with a pair of Thermalright AX-7s fitted
to 80mm variable speed fans running at 2800RPM and a Blue Orb on the Northbridge.
Both processors were very evenly matched, never varying from one another by
more than a single degree.
With liquid cooling, the CPUs are not running as close to each other. The processor
being cooled in series with the Northbridge cooler runs two to three degrees
warmer than the other. We'll be running some tests to see why that is in the
coming weeks, but will tolerate the difference for now.
During the initial tests, temperatures were topping out at 45 and 48 degrees
Centigrade, respectively. "Cruising" temperatures were about 41 and
44. This was with the pair of 80mm fans pushing air at the radiator. These fans
spin at 2500 RPM and are pushing 33 CFM each.
Not particularly happy with those numbers, we added a variable speed 120mm
Enermax fan running at 2300 RPM on the back of the radiator to pull air. The
80mm intake fans remained in place. Temperatures fell to 41 and 44 under load,
dropping to 35 and 38 while cruising.
I really didn't want a large fan hanging on the face of that nice radiator,
so we tried removing the two intake fans and putting the 120mm fan inside the
shroud. This increased the temperatures a couple degrees, this seemed like the
best all around arrangement.
Next we tried a faster 120mm fan inside the shroud. It supposedly pushes 118
CFM, but I don't have any other information on this fan. It did drop the temperatures
under load to 40 and 42 degrees under load, respectively.
A similar 120mm fan with an aluminum housing is on order. It will be permanently
mounted an inch away from the front of the radiator and connected to the Rheobus
for speed control. Hopefully this will perform about the same, or a little better.
After some lengthy discussions on the forums about flow velocities and radiator
efficiencies, it came to light that a higher volume pump might further improve
temperatures. To test out the theories, I ordered an Enheim 1250 pump with flow
rates over 300 gallons per hour. If you are interested in tracking the results,
keep an eye on the AthlonXP
forums in the Chill Zone section. I'll be posting updates there in the coming
weeks.
Final Thoughts
This is where things get rather anti-climatic. There just aren't any telltale
signs of liquid cooling on the outside. Things are considerably quieter but
the only visual differences are the lower temperature readouts on MBM5 in the
system tray. Unless you take a peek in the side window, you simply wouldn't
suspect there's liquid pumping through her veins.
Building this liquid cooling system taught me a lot and was plenty of fun from
beginning to end. It gave my "double-wide" case design a real purpose,
something that was a bit lacking before. Most importantly, I am now convinced
that liquid cooling is not only more efficient and quieter than air cooling,
it is also relatively simple to install.
Being rather new to building computers, I'm amazed at all of the possibilities
available to anyone building a custom PC. I thought using two processors instead
of one would be the last change for a while, but now its clear there really
is no end in sight to the possibilities.
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