The airspirit Watercooled Rackmount Project Phase 3
Pro/Geeks!               By: Airspirit 6/04/03

The Phase 1 machine runs significantly hotter now due to the new processor, and it is now using the Maze 3 block on a 1/2" cooling loop.  I'm jumping ahead of myself a bit here, since I haven't discussed Phase 3 yet, but when run by itself with the other two PCs off, it is running 46C idle and 50C load.  This is significantly WORSE than the previous temps, even when using a significantly  better water block.  This processor will be replaced as soon as possible, as I refuse to leave a processor this hot on my cooling loop, especially considering its poor overclocking performance.  Bear in mind that the other two loops I will be using (with the Black Edge blocks) narrow  down to 3/8" towards the water blocks, so this one block is getting about 45% of the total flow for the entire system.  In reality, it is getting (after Phase 3) approximately the same amount of water flow as one Black  Edge block was getting as of the end of Phase 2.

Notice the 1337 knitting yarn used to ensure my tubing clears my graphics card.  Space is definitely at a premium in this case!

was some of the nastiest algae that  I've ever encountered.  The stuff was like hardened Jell-O, and was  extremely difficult to remove from the loop.  I ran a high concentration bleach/water solution through my loop, rinsed it with water,  and still had some of the junk coating my hoses.  The bubble tube was then removed and soaked in hot soapy water, with no better results.  I  ended up having to blast the bubble tube out with a pressure washer, and then after adding my third cooling line refilled the system with 90%  distilled water and 10% Hyperlube anticorrosive additive, and that did the trick:  the gunk quickly was "dissolved" into the coolant, and now  milky white crap is floating in there.  For the purposes of this article, I will leave the gunk in the system.  I want to run the loop  for at least two weeks to ensure that all of the algae is killed and  dissolved before draining, flushing, and refilling my system.  My blocks, radiator, pump, fittings, and piping showed absolutely no sign of corrosion during inspection, proving that the anticorrosive coating on the steel JIC fittings worked flawlessly.

Also, for the purposes of this article and probably permanently, I will be running the fans at full power.  The combined noise from all of the case fans, PSU fans, pump, and radiator fans now  approaches 52 dB.  This is mostly low pitched, so it is not nearly as annoying as a high pitched delta fan, for example, and it is something that I  have grown to be able to ignore.  It is on par with being inside the cabin of a quiet diesel pickup when the engine is not accelerating:  you know it's there, but it isn't an annoyance.  The reason for this is that I have increased the bypass width to increase overall flow and added another 80W heat load to the loop:  I will take absolutely no chances of general system failure.

I would like to start this with a critical review of the NForce2 IGP platform.  I have now installed over a dozen  different NForce2 boards, and I've had great success with all of them ... except for the IGP boards.  With identical memory and processors, they consistently clock much lower than the SPP boards.  I have clocked the  above Palomino to 1826 Mhz rock stable in my 8RDA+ board, but it will not remain  stable over 1676 on the 8RGA+.  This is the third NForce2 IGP board I've installed, two of them being the 8RGA+, and one of them being the ABIT NF7-M,  and all have fell far short of the overclocking potential of the SPP versions of that board.  I am not sure if is a manufacturer problem or a fundamental  problem with the IGP

Another NForce2 board, another Vantec Copper Iceberq.  I swear by those things.  Note the the well organized power cables.

Without the expansion cards, installation is much easier.  The rolled tubes of tissue paper and duct tape at the entrance along with the duct tape wrapping of the tubing prevents the entrance edging from  damaging the tubing.

I found quite quickly that I  may have a problem with adding a fourth PC to the cooling loop.  Currently, the weight of the three PCs tops out at around 110 lbs, with a 10 lb printer straddling the whole mess.  Combine this with the weight of  the hoses pulling down (small, but not insignificant), and you have quite a bit of weight to be supported.  Looking at the diagram of how the  rubber feet on the base of the cases sit on the top of the others, you can  see how problems may be caused.  Since I have removed the roof brace to  allow room for the water blocks and tubing, there is nothing under the feet in the lower cases to support the weight except for the strength of the sidewalls of the case themselves combined with the anti-flex strength of the  top sheet of metal.  This is a bad situation, and I have noticed minor bowing in the bottom case's top.  A fourth PC would probably cause damage at best, and outright collapse at worst.  These are not heavy duty cases ... imagine jumping on a cheapo case repeatedly, and you would  see the reason that this may be a very bad situation if I continue my PC stacking without a supportive rack.  Since I don't plan on adding a fourth PC to this system, I won't be adding a rack.

On to the fun:  when adding this machine  in, I decided that I would stay with the previous structure and place the  slowest machines on the bottom and the hottest machines on the top.  The  reason is that the slowest machines will dump the least amount of heat into the  system, but being at slightly higher flow it would clear the radiator better.   The hotter machines, however, will be run a little hotter from flow starvation, but it will allow the ΔT to remain as high as possible, allowing the portion of  the flow that gets routed through the radiator to be cooled as effectively as  possible.  This machine will be placed in the middle of the stack, with the Phase 1 PC on top and the Phase 2 PC on the bottom.  On a more practical  note, I will be tinkering with my gaming rig more than the other two, so having it up top makes that a bit easier.