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Electronumerograph Part Two: Clean, Quiet and Cool. |
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Written by Tom Mordasky
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Tuesday, 20 November 2007 |
 The organization and design of the interior of a good quality mod is as important as how it looks from the outside. Building the chassis of the electronumerograph took an entire month of late night knuckle busting. I found I had little time to devote to the chaos of wires and components inside the machine. An astute reader will notice that the original guide, as entered in the challenge, does not feature a detailed interior shot. The situation was so desperate that whenever the case was opened the tangled mess of cables would bulge outward, and the case could not be closed again without first stuffing all that mess back inside. Bad news…
While building the highly stylized exterior was a lot of fun the
electronumerograph was destined for a very specific roll, that of a
media center. My wife and I both use laptops in out home, our printer
and music have long been wireless with no central desktop machine or
desk as in a traditional computer set up. I wanted a robust machine to
serve as the center of it all, providing all of our entertainment as
well as backup and storage. The dual 1ghz G4 with several hundred gigs
of storage fit the bill perfectly.
Well there is always a catch to any plan and this one was no exception.
The Quicksilver sounds about as loud as a vacuum cleaner when you are
sitting quietly in your living room trying to listen to the dialog of a
movie. Furthermore the entertainment cabinet where it resides is
partially enclosed, causing heating issues right off the bat. The
machine froze the first time I ran it inside the cabinet. Clearly
something needed to be done.
So quiet and cool, here we go. Googling around for info on the stock fan configuration I came across the following specs:
Primary Case Exhaust 120mm fan = 86 CFM 37 dba
PSU exhaust 80mm = 38 cfm 29 dba
CPU intake 60mm = 23 cfm 33.5 dba
There are three fans inside the Quicksilver, to me the 90mm power
supply fan seems the loudest. The first thing I did to quiet things
down was remove the metal grill from the back of the PSU. This mod is
quick and easy and well documented on xlr8yourmac.com. It did have a
noticeable effect on the noise level. But to really quiet things down
more drastic measures were needed.
Quiet fans are quiet not only
because they are better made but because they don’t spin as fast. A
slower fan moves less air than a fast one, making an already poor
cooling situation worse. So what was needed was not just a swapping of
fans but rather a careful re-planning of the airflow throughout the
case.
The Quicksilver’s PSU and main 120mm fan are both exhaust. The only
intake is the 60mm fan attached to the CPU heatsink. When the machine
is in its normal, upright position the intake for the CPU is just to
the left of the exhaust from the power supply. Turn the machine on its
side as I did and the intake is now above the exhaust, bad news. The
CPU is sucking in hot air from the power supply. Grrrr….
My first fan purchase was a pair of 90mm silent fans from Ultra. They
were rated at 19dba and 24cfm. The first fan I replaced was that of the
power supply. It was wired directly to PSU's internal connection. The
noise of the machine was immediately cut in half. For the big 120 mm
fan I chose a Thermalake thunderblade rated at 78cfm and 24dba. It came
with a bonus: 3 blue LEDs which matched my case quite nicely. The left
vent in the chassis had yet to be used and it was the perfect spot for
the new primary intake. The two large side vents were now both pulling
in cool air, with the four 60mm hard drive fans on the right and the
single 120mm on the left.
Now to tackle the processor itself. The original set up was a no go as
it simply fed warm air from the power supply over the heat-sink.
Additionally the new, silent 60mm fan is only rated at 16cfm, half that
of the original. Therefore I chose to mount two 60s. One fan was
mounted in the original position and a second on the inside of the
heat-sink. Both channel air across the baffling and out the back of the
chassis.
To finish the job I mounted the extra 90mm fan I had to the
bottom of the chassis, in the former position of the 120mm. This give
an extra exhaust point and pulls heat away from the video card and PCI
bus. The CPU fans are connected to the motherboard, the others are
wired to the Musketeer fan controller mounted in the front of the
machine. All of the new fans were three wire models. For two wire
connections like that of the motherboard I snipped the connector
off the old fan and soldered it to the red and black wires on the new.
I left the yellow wires disconnected. Seems to work just fine.
Wrapping up all of the cables took some planning, I think I tore
everything out and put it all back in around five or six times before I
felt everything was right. Now there is no clutter and most importantly
very little noise. It’s hard to rate success in this project, once
silence is your standard it’s a pretty high bar to shoot for. The
computer’s noise level is lower than that of my fridge. (Pay attention
in a quiet room at night, you will hear the hum of your fridge too.) It
is quiet enough that the spinning hard disks are louder than it and the
DVD drive is much louder. The 120mm fan gives off a bit of a hum due to
chassis vibration, the addition of a gasket should solve this.
The new airflow pattern pulls fresh air into the sides of the chassis and exhaust out the back.
Now the electronumerograph is rocking Frontrow and quietly taking over my entertainment system. That’s right, quietly.
Electronumerograph Part Three is coming soon, In which I will outline
the software and hardware set-up that brings my Mac media hub together.
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