Water-Cooled Borg Cube, Part 1: Planning Phase

aka Bob is assimilated by his Borg Cube...

Everyone knows that a Borg Cube has got to have a warp core somewhere, right? That's how they manage faster than light travel, after all. And the eerie blue glow cast from the Cube's window portals could certainly be mistaken for Cerenkov radiation generated by energetic tachyons leaking from that core. In any event, before I fracture the whole Borg fantasy thing too much further, let me get on with telling you about my project to water cool the Borg Cube.

But Why?

Okay, fair enough. Why water cool? What was broken that needed fixing?

There are two reasons at work here, one very strong, one is really just a rationalization.

First the rationalization: my current Zalman air cooling HSF (that's heat sink and fan to you Noobs reading this) is not really cutting it. Things heat up a tad, and my operating temps are normal in the 50-60C range on the CPU. That's tolerable, but I can't really get much of an overclock with that. Now there's reasons why this is happening. That Zalman is very well reviewed and is capable of doing a much better job cooling, except that I modded it. I took their perfectly reasonable fan bracket, and turned it into a window mounted fan instead. This way I can admire the beauty of the Zalman flower heat sink. However, in the process, I have a fan that's a little further away than factory spec and it just isn't doing the job it should. In fairness, my brother solved this problem in a very elegant way. He simply constructed a nifty duct for his and presto! He gets decent temps, more like the low 40'sC that ought to be possible with this cooler. Still, I know water cooling can get me to much lower temps and make for a decent overclock.

Now to the REAL reason for water cooling the Borg Cube. It's just too cool to miss out on! Have you seen water cooling rigs? The aesthetics are just so right, plus, this just says bleeding edge of technology in a way that no air-cooled HSF can match, no matter how exotic. If you have any doubts, check out some of the playpretties available to the water cooling fraternity:

Water Cooled PC Gallery

So let's get down to brass tacks and get it done, get it done right, get it done Borg...

What About Peltier Cooling?

I did spend a fair amount of time researching Peltier cooling. It's interesting and very bleeding edge. Peltiers are like thermocouples in reverse, and are what R/V refrigerators and the like use to chill without a heavy compressor. Typical installations also plumb cooling blocks onto the graphics and motherboard chip sets. Add a set of heat spreaders and sinks to your RAM and you have now reached the pinnacle of PC cooling technology. This is what macci uses to get his insane overclocking to work. There are all kind of problems with a Peltier rig:

      Condensation. Anything cooler than ambient can have condensation. You have to jump through serious hoops to control it, and even then, you still read about it "eating" a fair number of systems.

      Power. Peltiers are very juice hungry, so you have to provide a whole separate power supply just to feed them. For a 226W Peltier, which is the big dog, I gotta come up with 300-400 watts, and at voltages not necessarily convenient like 16V instead of 12V. I've yet to see someone sell the ideal adjustable off-the-shelf Peltier Power Supply. The hacks that are available are going to use up space in the Cube, and they're going to add heat. Not to mention do I really want to pay the electricity for a 1 kilowatt PC?

      Cooling. Cooling requirements get much more serious where big Peltiers are involved. To really make them shine we must provide special active cooling for all the key components: CPU, GPU, mobo chip, RAM, etc.. The water cooling system had better be awesomely efficient to move all of that heat outside the case. There's just less margin for error all the way around. Again, I'm not sure there's room inside the Cube for all this stuff, and secondly, the really heavy duty systems are ugly.

I'm not sure I ever found a picture of a finished rig that didn't look like Dr Frankenstein's laboratory. I have reluctantly concluded this is TOO far out on the bleeding edge. If I want to run some Radical Overlocking experiments, I figure I'll just unhook my hoses and use an external source of very chilled water. I think I will try to waterproof my CPU socket area to guard against condensation, but this can wait until I swap mobos.

Planning and Parts

We've answered the "Why?", so now its time for a bit of the "How?". Water cooling can be a bolt-on modification, but it is one of the most extreme tasks for a case modder. I would say only the complex display projects and the business of adding a window to a hard disk are more difficult. I'm not sure I'll ever get to the latter, but there are already plans in the works for the former. Given this level of complexity, it behooves the intrepid modder to take a little time planning things out. For one thing, there is the issue of making it all fit. Water cooling is rather bulky. Fortunately, the Cube has got quite a lot of space. Secondly, there is the issue of making it all LOOK GOOD. Also very important, and a reason to plan and research. I spent extensive time reviewing the many forums on my list of PC links to educate myself on the ins and outs of water cooling.

Suffice it to say that the machine that comes closest to matching my vision is Mashie's "Syrinix":

Mashie's Syrinix

What really captured my attention here was that this looks like a system that was engineered rather than just thrown together. Hose runs are kept to a minimum. The pump is oriented to try to minimize extra bends in the tubing that will create back pressure. There's even a 12V relay system that kicks on the pump whenever the system is powered up. Mashie has also fabricated an elegant solution to the ducting/shrouding problem that blows cool air through a heater core and out the bottom of the case so that the heated outflow will not raise his case temps. Finally, he is cooling all the critical pieces: mobo North bridge, GPU, and CPU. Bravo!

Mashie's look is not quite right for the Borg Cube, however. I don't want so much copper, for example, so I probably won't use all the copper right angle bends. Also, I want to avoid bringing too many obstacles in front of the mobo. Mashie's system looks like it will take some disassembly and draining if he wants to add a memory module, for example. Finally, Mashie is not using a reservoir, and I want one.

I've divided the construction of each component into its own little web page, and you can check them all out here:


Radiator: Through the use of a nifty downloadable searchable database of heater cores, courtesy of Radac, I have discovered that the heater core from a 1984 Chevy Cavalier with A/C measures 8 X 5 5/8 X 2. That will fit!

I'll need to build a fan shroud for a 120mm fan drawing air into the case through this baby.

AutoZone $22.99

Reservoir: I used a little Danger Den res with a fabricated plexi bracket to hold pump and res.

Pump: AquaVia 1300. 370gph and cheap at BeCooling!





Water Block: Is a special homemade block built by converting a Swiftech MCX 462 air cooling block for water cooling. The cost is due to all the tools and materials I've had to buy... $120.00?
Tubing: The hot ticket is called Tygon and is available here, here, and of course here! The latter is usplastic, where I got my acrylic stuff, so I'll probably order from there. Think of it as combining all the benefits of silicone tubing with crystal clear finish so we can see the throbbing heart of a water-cooled Borg. $2/ft


Some of the initial batch of materials laid out: 1/4" acrylic sheet, 1" acrylic rod, heater core, copper sheet, 2" acrylic disks, arcryic cement.

Here's what all that plexi turns into...

Temperature and Flow Rate Measurements

A flow rate test rig...

It's pretty straightforward to measure flow rates. I simply used a gallon bucket and timed how long it takes to empty the bucket as I added each component. Here are the results:

Just the Pump 25 seconds This Via Aqua pump is supposed to be able to move 300 gallons per hour. Turns out its really good for about 144 gallons per hour!
Pump + Radiator 28 seconds Not only are heater cores efficient heat exchangers, but they do not restrict the flow too much. We go from 144 gallons/hour to 128 = about 11% restriction.
Pump + CPU Block 38 seconds 95 gallons/hour = 34% restriction.
Pump + Radiator + CPU Block 38 seconds Still 95 per hour.

The Myth of Turbulence and Flow Rate in Water Cooling

Borg Cube Water Cooling To Do List

What's left for completion of the water cooling:

  Get some hose clamps

Cut hoses, assemble, and leave running 24 hours to look for leaks.


Fabricate and install fan lighting kit with Laser LEDs.


Plexi Fan Spacer

Plexi Fan Spacer Lit

  Mount 120mm fan on radiator.
  Build plexi UFO base.
  Disassemble case.
  Install UFO base & water cooling

Late Breaking News: Swiftech + Peltier

Before I even get finished with my water block (actually, it was finished, but not yet installed), I read about this radical new offering from Swiftech:

Yes folks, it's a Swiftie air cooled HSF with factory installed 226W Peltier active electronic cooling device. Woof!

This thing is so sweet. Some day, I need to buy one and mod it like my water cooled block to pick up Peltier cooling. Would be so excellent!

What About the Graphics Card?

Yes, I have plans here too mates. Check out the new Tyan Tachyon 9700 Pro video card:

Tyan Tachyon 9700 Pro...

The card is sweet all by itself. But consider this: what if I pulled that fan outta there and stuck a water block in its place? We can view the blue heat sink as more of heat spreader in that case. I think its totally doable and the end result would be awesome!

A round block something like this would be needed...

The end result might look a little like this...

Back to the Borg Cube Collective...

All material 2001-2006, Robert W. Warfield.