Intro
In addition to reading about quiet components and noise reduction, I’ve spent considerable time learning about watercooling, knowing that I would try it eventually.
Now is the time.
With watercooling, my PC finally gets a name: Project QBG - Quiet But Ghetto. The pictures should explain that well enough. If a case by MNPCTech or Mashie is the polished CAD rendering that Boeing shows to the Pentagon, my system is the cardboard and duct tape contraption that the engineers actually used to design the thing.
This thread will document the system’s current state and include specific information about my silencing and watercooling techniques and experiences. While this is neither a worklog nor a how-to, I hope most readers will find something of interest here.
Starting Point
I haven’t built myself a completely new system since September 2000, though no parts of that computer are still in use here. This PC’s configuration is the result of several years of steady upgrades. About a year ago, I got serious about quieting the machine and moved everything into a new case which was modified for lower noise. More recently, the PSU and HD have been changed for quieter components, leaving the following setup pre-watercooling:
• Chenbro Genie SR10405, modified
• Seasonic Super Silencer 350 A3
• Zalman CNPS-7000AlCu
• Intel P4 2.4C (Northwood)
• Abit IC7
• PQI PC3200 Turbo 2x512MB (Samsung TCCD)
• Visiontek Geforce 3
• Samsung SP1614C (JVC motor)
• PDC 52x CD-RW
• 3.5” floppy
• Chaintech AV710
• Linksys NIC
The Zalman HSF and stock NB cooler were both controlled by Speedfan. After much experimentation, I set the CPU fan to 28% idle (~930rpm) and 40% (~1400rpm) above 55C. The NB ran from 40% to 50%, or roughly 2300rpm to 3000rpm. Other cooling included:
• Sunbeam Rheobus, controlling the case fans
• Evercool aluminum 120 exhaust, lower rear, <4V
• Panaflo 92M1A exhaust, upper rear, ~5V
• Enermax 80, ziptied to GF3, ~5V
This was a very quiet PC but remained audible in my even quieter room. At idle, the PSU produced the most noise, though the Panaflo 92 ran a close second. Under load, the Zalman HSF became audible. The SP1614C is isolated with a combination of Sorbothane and elastic, and I’ve never noticed any drive noise.
Case Modifications
I bought the Genie from Coolcases as part of a silencing upgrade a year ago. I removed the fan grilles, damped the side panels with McMaster 54665T32, and lined most of the case with the foam from McMaster’s melamine ceiling tiles. For convenience, I added casters and handles, but have detected no noise benefits from those changes.
This case proved an excellent foundation for a quiet PC. And that’s the right word, since the PC is extremely heavy. The damping works wonders against chassis resonance, and rapping a panel gives a dull thunk with no ringing. The combination of the Genie’s rear-mounted HD cage and the damping materials prevents drive noise from escaping the front of the case. Airflow in this case is well designed and effective, as is the large intake filter. I could nitpick a few areas, but this case is an excellent choice for anyone who can accommodate its size and price.
I selected this case partly for its suitability for watercooling. Thanks to the Genie’s large open space in the lower compartment, a large radiator fits easily with minimal mods. Knowing that I would run my fans as slowly as possible, I decided that the open 120mm intake would be sufficient and did no more cutting as part of the WC conversion.
WC Components Used
All of my reading indicated a few simple rules for quiet watercooling. Fundamentally, WC is aircooling with a complicated ducting arrangement, so most of our usual airflow goals apply.
To flow air through the radiator quietly, you want a radiator with a lot of frontal area, reasonable thickness, and open fin spacing. I elected to use a heater core for its good price/performance ratio and went for the biggest frontal area I could fit. The core is for a 1995 Chevrolet G Van (Fedco 2-333 or GDI 399095) and has rated core dimensions of 9-1/2” x 7-3/8”. Mine is slightly smaller than rated and an excellent fit in the Genie. While the core’s 2” thickness is greater than ideal, I believe the large frontal area compensates. This core offers almost twice the area of the popular Chevette/Pro-120 cores, and about 50% more than a Black Ice Pro 2.
For the CPU waterblock, I was lucky to get a Storm G4 from Little River Waterblocks.
Any temperature advantage available in the block should allow a slower fan or pump speed, so a quiet system needs a good block. The G4 is a good block. Mine came configured with ½” barbs.
Getting a quiet pump was essential. In addition, I wanted a DC-powered pump, so the current choices were the C-Systems CSP-750 or the Innovatek/Eheim HPPS. Edward Ng’s used CSPs were available for a fraction of the HPPS’ price, so the decision was made.
Other Parts & Supplies
McMaster-Carr, the local hardware store, and the auto parts store were raided for additional parts. These included 7/16”-ID Masterkleer tubing (only $0.36 per foot!), various hose fittings, hose clamps, weather stripping, water-pump lubricant/corrosion inhibitor, etc. A project like this can go a lot faster when you remember to ignore Home Depot and Lowe’s and find a REAL hardware store.
Installation Steps
I will just touch on the highlights here, with the understanding that there’s more to installation than detailed here.
The radiator’s hose fittings required modification. I removed the ends of both tubes and epoxied ½” brass barbs onto the remaining pieces. Because the core’s tubes run at an angle, I couldn’t get as tight a mechanical joint as I’d hoped, but the connections passed a pressure test after letting the JB Weld set up for 24 hours. This qualified as Good Enough.
I had decided to use the case as my fan shroud, so the HC was mounted to the chassis’ front panel with zip ties and 1” nylon spacers. These secure the core very well while requiring almost no work. The core is sealed to the case with weather stripping and scrap foam so that all intake air must pass through it. The case’s side panels must be installed for proper cooling.
Mounting the waterblock was extremely simple, though it did require removing the motherboard and the stock HSF retention frame. No real secrets or tricks here.
The real art of watercooling lies in hose routing. I wanted to use the least amount of hose possible, so the pump is suspended at the same level as the waterblock and radiator fittings. The whole loop has about 2 feet of tubing.
I mixed distilled water with the recommended dose of Prestone pump lubricant and 1 drop per gallon of dishwashing soap. This is probably the cheapest acceptable blend available.
Installation Issues & Problems
While I suffered no serious problems, various smaller issues arose. These affect convenience more than performance, but will lead to changes at some point.
The HC’s connections are the system’s high point, and this makes bleeding a giant pain. I’d thought that tilting the PC during bleeding would solve this problem (It works fine on a shifter kart…), but it has not been as fast as I’d hoped. When I redo the loop, I will happily add more hose if it allows better bleeding. With my modest water flow, I don’t believe that an extra foot of tubing will hurt my cooling significantly.
The HC’s angled connections limit my mounting options. This was no problem for my initial setup, but it will prevent inverting the radiator. To solve this, I’ll need to break out a torch and replace the curved tubes with straight copper pipe. And JB Weld seemed like such a time saver. Sigh…
The 1” spacers I used between the HC and the case are a little too short. The Genie’s bezel hinges force the HC to a small angle. Easily fixed next time.
I ordered 5/8” spring hose clamps from McMaster for my 5/8” OD tubing. They are great clamps, but absolutely will not fit over the tubing when it’s mounted on a ½” barb. I am incredibly foolish and running without hose clamps at the moment. For this reason alone, my redo will probably be soon. To be honest, the tubing is very secure on ½” barbs, and I’ll probably need to cut it for removal. Careful eyes will notice that there is one clamp in the system. I put my T-line too near the pump’s intake, and the tubing didn’t quite seal on the pump. Using a worm-drive clamp stopped the slight leak, though I should have seen this problem in advance – there’s almost no tube between the 2 barbs.
Results
Surprisingly good, but also disappointing.
The CPU temperature is great – something around 10C less than with the Zalman. And no fan ramping up under load! FWIW, the IC7 reports roughly +17C over ambient when idling and +35C under CPUburn. Considering the IC7’s reputation, those numbers satisfy me. The 120 exhaust still runs at <4V (below startup voltage), which gives extremely low airflow. Regardless of fan speed, the 2.4C refuses to clock ANY higher with WC. EDIT: I've been running at 260FSB, or 3.12GHz, with 1.625V set in the BIOS. Not too surprising for a P4, but I’d hoped for a little something extra. However, this does mean my heat production hasn’t changed, and the temp comparisons are as meaningful as mobo readings ever get.
Initially, I had a problem with the PSU fan ramping up. Not too surprisingly, the Seasonic didn’t want its air preheated by the radiator. Because my Genie has a door over the external bays, a traditional PSU duct wasn’t possible. So I tried to come up with something more ghetto for the truly lazy WCer. With painter’s tape and a scrap of foam, I partitioned the Genie’s top compartment into a separate zone. Next, I used the Rheobus to turn off the 92mm exhaust. With 3 minutes’ work, the PSU pulls ambient air in over the hard drive, and I eliminated a fan. Very satisfactory engineering! Under long-term load, the PSU fan ramps up to ~1350rpm, only 100 above idle.
With 2 fans removed, pump noise became an issue late at night, when a faint HD-like whine came through the case. Running the pump at 8-9V solves this problem completely, but costs ~2C on the CPU. However, the SS becomes the loudest component, even at idle. Having a Super Silencer A3 as the “noise problem” in my system, I am perfectly satisfied with its noise signature. I’ve been living with its current configuration for about a month and have noticed no irritating noises.
Conclusion & Thoughts
For a mechanically minded gadget freak, watercooling is cool! I have significantly improved temperatures and noise compared to a quality HSF, and I blame this system’s inability to OC higher on my P4. However, I suspect that ducting an XP120 to the 120mm exhaust would have given better results by a price/performance standard. Such an approach would have required less work as well.
My results reflect a WC system that prioritizes low noise in a self-contained system, and I’m delighted with the outcome. I firmly believe that a good watercooling implementation requires significant costs in time, space, case modding, and money. While I accepted all that, newbies should approach watercooling with open eyes rather than expecting water to perform miracles by itself.
There are a couple of areas that I still wish to improve. The hose routing needs a better layout for filling and bleeding. In addition, I’d prefer to replace the aluminum pump to avoid any galvanic corrosion issues. I will inspect the components when I replumb the loop and report any problems. Finally, Zerex Racing Super Coolant should be a better additive than the Prestone lubricant, so I’ll make that change too.
Pictures
Clicking the thumbnail will give a somewhat bigger picture. Links also included to the official, Monster-Sized shots (in case you want to count the dust motes on my soundcard). The biggies are approximately 2-3MB, so consider yourselves warned. BTW, the Image Zoom extension for Firefox is very nice indeed.
Monster
Monster
Monster
Monster
Maybe it'll annoy me if I swap the PSU fan.
I really like the design of no fans on the HC and having the exhaust fans do the work. Very efficient design. Been linking this thread all over.
