My Water Cooling System

The experiences of a first time builder. — Jason Padrick.

I have always wanted to construct my own computer rig. Over the past few years I have learned a lot from a friend in high school, enough to build my own. I needed a new computer for college, so I finally had the chance to prove that I could build one.

My friend and I found out about water cooling on Overclockers.com, and decided that this was the way to go in terms of noise and cooling performance. I’ve been keeping an eye on all sorts of water cooling components and decided that I wanted a closed-loop system. I wanted to build the highest performance system I could think of a reasonable cost to me.

It took me a long time to figure out how I would do this, but it was even harder to get my father to approve of this. Computers to me now are what cars were to him 30 years ago. He didn’t understand that. He gave in and decided to help me when I showed him my new “cool toys”.

• Epox 8KHA
• AMD Athlon 1400 AYHJA
• 256MB Mushkin PC-2400
• IBM 40GB 60GXP
• Guillemot Kyro II
• Philips Acoustic Edge
• Linksys LAN
• Hauppauge WinTV
• Lite-On 16x10x40 CD-RW
• DigiDoc 5
• Monsoon MM-700 speakers

The cooling parts I settled on were a Swiftech MCW-462. I chose this based on the performance reviews I read. The Danger Den Maze 2 looked good too, but I liked the swivel connectors on the Swifty. I chose the Eheim 1048 because of its noise levels and high pumping capacity (I bought it on Swiftech’s site).

I liked The Blackice radiator with ½” connections from Overclock-Watercool
because of its heat dissipation capacity, the size, and the built-in 120mm fan mounts. I chose the Chenbro Junior case because it has the perfect location for the radiator and dual 120mm fan mounts. It was small also and I didn’t want a full tower. The Enermax power supply has a reputation for low noise levels and reliability, so I bought that too.

I wanted a water reservoir to make the system more convenient to fill, and it took many trips to the hardware store to get the parts I needed. The reservoir took several adapters, a T-joint, a 90 degree elbow, a splice, a cap, and a ½-½” barb.

I read about vertical reservoirs having vortexes pulling air down into the pump, so I though having a T-joint horizontally would give enough volume and prevent these vortexes. Since the air would only be in the highest portion of the T-joint, it would be partially isolated from the water flow. It works without any problems.

I replaced the pump outlet pressure fitting with a ½” barb because the ½” OD tubing would just fit right over the inlet on the Swifty. I put hose clamps on all barbs and fittings just for good measure. The water block needed it because the fluid would lubricate the fitting and the hose would pop right off. I had hoped that the ½” tubing would increase flow rate somewhat and ease the stress on the pump.

One problem I had filling the system was that the air would get stuck in the 90 degree elbow on the inlet side of the pump, since there was not enough water flow to force them into the reservoir and out the T-joint. I solved this by cutting a short length of tubing and pressing it into the barb fitting.

The tubing was the same inner diameter as the barb, so flow rate was not compromised while providing enough water pressure to push all of the air into the reservoir. I used a 50/50 mix of distilled water and antifreeze. I know it isn’t the best for heat transfer, but I couldn’t find any water wetter at the auto parts store.

I wanted to mod the case a little to allow for better airflow into the case, so I cut out the front and rear 120mm grates. I taped the holes in the case on the front with laminate tape so that most of the entering air would go through the aluminum mesh filter.

I connected the Eheim to the power supply by using a 24V relay. The relay was activated at 11 volts, so running it off of a 12 volt rail wasn’t a problem. At first my father and I connected it to one of the fan ports in the power supply, not knowing that it was voltage regulated by the 80mm fan on the back.

This was quickly solved by cutting one of the lines going out of the power supply and pulling it back through. I had to remove the 90 mm fan in the Enermax because the fan grill interfered with the mount in the case. I couldn’t easily modify the mount so I figured one less fan would mean less noise anyway.

The 110V connections were sent through the rubber grommet with the rest of the drive power wires and around the right side of the case, where I used some connectors and an auto fuse holder. I grounded the pump to the case with a ring screw-down.

I modified the motherboard with an old, passive heat sink that I yanked from a Pentium 200. It looked more than adequate for the task of cooling the northbridge of my Epox 8KHA. I have since taken my Volcano II, removed the fan and epoxied it to my graphics card, since its fan started to fail. In both situations Arctic Silver epoxy was used.

Once I filled my water reservoir and ran it for a few days to check for leaks, then it came time to stuff it all in the case and give it a go. Installing the water system is a pain since one needs a third hand to handle all three parts flailing around. I turned on the system, the graphics card bios came up and the screen went blank. The pump didn’t turn on either.

I turned off the machine. This is when my father and I figured out that the relay wasn’t getting enough voltage. It still didn’t explain why the screen went blank. I double checked everything! We get the pump working and turn on the computer again. The pump works, the few fans I had in there were turning, and no screen. I smelled a little smoke and saw that the thermistor I had attached to the water block was rapidly rising over 40C.

Now I had a better idea of what happened, and my heart sunk. My 1333 AYHJA Athlon had fried! I took the water block back off and found that my Arctic Silver didn’t even touch the core. The standoffs for my water block were higher than the core. The shoulder washers weren’t seated in the mounting holes since the holes were too small.

The water block cleared the CPU by about 40 thousandths of an inch. A couple weeks later, when I came home from college, I installed my new 1400 AYHJA. My father and I made cardboard washers that were the right height and let the water block touch the core. It is painful to have a P200 with Win2K for a few weeks when I was just starting to enjoy the blinding speed of an Athlon for the first time.

Now it is time for the fiery realm of overclocking. I bought the Epox 8KHA partly because of the BIOS multipliers and I intended to put them to use with my unlocked Athlon. I managed to reach a 137 bus speed but the performance increase was small enough that I took it back to 133. I run with a USB keyboard and mouse, so I couldn’t go higher anyway.

I took the voltage up to 1.85 and started chugging away on the multipliers. I reached 1600 stable, but the CPU wouldn’t even post at 1733. I tested for stability with SiSandra’s Burn-in wizard on the CPU benchmark and Multimedia benchmark for 20-25 runs, until the temps reached a maximum. The water block thermistor is mounted under the Swiftech’s water outlet on the copper. I am not using Arctic Silver at this time.

• Ambient: 20C
• Idle: 32C
• Load: 35C
• Before radiator: 28C
• After radiator: 30C
• C/W: 0.159

Not bad. I was happy with that. I was running the Panaflo L1A at 10V. I tried to use a pulse-width modulated fan controller, but it made the fan tick, so I will eventually use a linear controller. I took it down further to 5.8 volts by crossing the 12V and 5V lines. My new temps are as follow:

• Ambient: 23.4C
• Idle: 38.0C
• Load: 39.5C
• C/W: 0.171

It’s a little warmer, but now the 120mm fan is quiet enough that I can’t hear it. The C/W is still as good as the best air coolers. The power supply fan and the hard drive are the noisiest now, even though I can tolerate them while I sleep.

I’d say that for my first computer system and my first water cooled system, it works as well as I expected. I still need to improve upon it. The hose going from the radiator outlet to the pump inlet needs to have a 90 degree elbow because the hose is crimping on itself slightly when the water gets warm.

I need to place Arctic Silver on the CPU core, and I need to replace the fluid with distilled water and water wetter. I bet I could lower my temps 5C more than what they are at now. I also want to place a Papst 80mm fan in the power supply. For now, my computer runs well. I read a quote once:

“Regular people say ‘if it ain’t broke, don’t fix it’. Engineers say: ‘If it ain’t broke, it doesn’t have enough features yet.'”

I believe the same applies to overclockers and water cooling.

Jason Padrick