GOAL: fast but silent

First of all a fast chip such as the P3.06 puts out a massive 80W of heat. Overclock it and you increase that even further. Any fan that cools it sufficiently and without detriment to the rest of the system temperature will make a lot of noise. Many of the latest dual ddr memory motherboards now come standard with a noisy fan on their northbridge chip - remove it and the chip gets to well over a perilous 60 degrees in no time. Add in a hard drive, a dual raid for your video framestore, a huge graphics card thats got more memory than a typical computer of only 12 months ago and finally a powerful psu to fuel everything and you are up to huge heat levels and a lot of noisy fans. Personally, my computer is not isloated in my house and the type of work I do means that I need as much speed as possible. So the brief, create a fast overclocked computer that was also as close to silent as possible.

So how do you build a fast system that is virtually silent ? Well the first thing is to watercool everything possible but then you need to cool the water. Three soltions: use an external reservoir like an underground tank or underground piping where the natural low temperature will constantly cool your water, use a radiator with strong but loud fans on it thats sited in another room where you won't hear it or lastly, use small diameter undervolted fans at slow speed but on a large amount of radiator real estate inside your case. Thats not all though, you need to pick your fans very carefully 'cos those that are marketed as "quiet" often aren't. You also need to decouple everything from the case to limit vibration and you will need to pick the right watercooling components and design the system carefully. Finally, as your case airflow will be lower than normal you have to pay careful attention to the components that we overlook but also need decent cooling from a steady flow of cold air through the case, e.g. the motherboard powerfets, the RAM and the graphics card RAM.




Initially i was taken in by the off the shelf solutions made by the germany company innovatek. Water and pipes and electronics and pumps and barbs and fittings scared the hell out of me at first so i opted for the safe route. The innovatek gear had been getting very good reviews on the net and seemed foolrpoof to set up giving decent cooling performance. I bought the full kit with small eheim 1046 pump, cpu and gpu waterblocks, Maxexpert rad and a slow undervolted 7v papst 120mm fan (along with panaflow respected as the quietest fans you can get). The rest of the system was standard good kit, gigabyte board, lian li case, lightning quick western digital JB drives, antec "quiet" psu, 1gb corsair XMS 424mhz ram. I cut into the case a fair bit to get it all neat and tidy and also to decouple the pump and make it totally silent. Fans and the psu were also mounted using either washers or rubber isolators to try and cut down vibration passing into the chassis or radiator.


There were a few problems with this setup. First, never buy anything that says "silent" on it. The antec psu was never quiet, just a huge source of "whoosing" in my book. Secondly, cooling was drastically reduced with only one fan on the radiator and also even further reduced when that fan was set at a quiet slower 7v and pushing far less air through. When the graphics card and cpu had to work hard my water temperatures went sky high and load was sometimes reaching 56 degrees C which is theoretically safe for a 3.06 chip but not really where i want to be. Also, with such low case airflow, temperatures inside would get too hot for my liking and i didnt like the idea of risking the mosfests on my board, my ram or my northbridge or hard drives - all which require respectable cooling. If I ran the rad fan at higher speed or indeed added a second fan in a push-pull configuration sanswiching the radiator then case temperatures obviously improved drastically and my hard drives stayed below 50C, but then noise was again a huge issue.

The first thing i did to counteract this was to add more radiator real estate. The fans can't get faster so maybe just add more slow almost silent fans on additional radiators. My solution was to add in a Black Ice Mirco2 radiator which covers x2 80mm fan slots. This helped considerably bringing my water temps down by 2C and the cpu idle by around 2C with more airflow into the case. All in all, the system was way way quieter than my last computer and for a while i was happy.

For a while that is though ! You see the problem with silence is that it doenst really exist. Soon as you remedy the loudest part of your computer at any given moment in time, another part then becomes then becomes noisy when before its presence was merely drowned out. Besides, i never really finished my goal and never enjoyed succeding in my original challenge. So having become accustomed to all things watercooling i decided to upgrade the whole lot for more complex and professional kit and also to go on to complete the full watercooling of all possible components as opposed to just the cpu and graphics card. Heres where I am now:





To realise my original ideas i calculated that the best way to manage lots of watercooling was to separate everything into 2 distinct loops each with their own pump but also sharing the same reservoir for convenience of filling, draining and general maintenance. The cpu gives out so much more heat than anything else so having its own single dedicated loop seemed appropriate. This loop would also have the most radiator power and the most powerful pump and be a 1/2 inch diameter system (more on this later).

Meanwhile, the secondary loop could run off a smaller quieter pump and use a single smaller radiator which would suffice in cooling the lower heat output of the graphics card GPU, the motherboard Northbridge and the two hard drives. Lower diameter 3/8 inch connections and tubing would be adequate for this auxilliary circuit.


Lots of slow silent fans pulling air through lots of radiators - thats the theory. There's a total of 3 radiators here.... lots of cooling interface to make up for the slow speed/low cfm fans. This means that the front of the case is all radiators. The rear therefore houses 2 aquadrive hard drive watercooling enclosures and this is convenient in that it removes their noise to the back of the case and also takes their plumbing outside the rear of the case to make for easier and safer access

The water reservoir likewise sits outside the case at the rear. It's easier to fill here and maintain and it can conveniently feed the two pumps through the bottom inlets and receive incoming water from the nearby cpu and hard drives at its uppermost inlets.





The first loop dedicated to the 3.06 Pentium4 which is overclocked to 3533 Ghz so puts out a whopping amount of heat. Water flows only through the cpu waterblock. This ensures high flowrate and no adidtional heat from other components. The cpu waterblock used is the Whitewater. These were developed and handbuilt by a chap know as Cathar out in austrailia.. at the time they outperformed all other waterblocks (although Cathar has since gone one better with the Cascade) by as much as 4-5C.

This loop uses large 1/2 diameter Tygon tubing with a strong Eheim 1250 1200 litre/hour water pump to again maximise flowrate. Whilst the innovatek gear is designed around slow flowing water and the blocks do perform well at this level, the golden rule is that increasing flow will always improve temperatures - the Whitewater block also comes into its own at high flow rates. Larger pumps introduce more heat into the system but ultimately the faster you can move the water across the surface of your waterblocks the the quicker the heat can be removed under load.

The radiators used in this loop are firstly the Black ice extreme and then the Black ice extreme 2 (which is essentially two Black ice extremes in itself). On the BIX I use a 92mm papst 3412NGL and on the BIX2, x2 Panaflo 24M1a. All these fans run at 7v.




Loop 2 takes water from the reservoir and through the lower powered Eheim 1280 600litre/hour pump. From there we go to a smaller Blick Ice micro2 double 80mm radiator which is fed air via two 80mm Papst 8412NGL fans again at 7v. The water then goes first to a danger Den Maze 4 GPU graphics card block on my Radeon 9800 pro as its the next most demanding heatsource after the cpu. Then the loop goes on to cool the northbrige of the motherboard using a Danger Den Z chipset waterblock modified to fit the canterwood board. Laslty, the water goes to the two enclosed Aquadrive hard drive coolers as they put out the lest amount of heat.



I use panaflo and papst fans. These are widely regarded as the quietest money can buy. They are all undervolted to 7v (down from 12v) but i do have them all on custom made switches so i can turn each of them off independently or run them at 12v just in case I require some extra cooling on very hot sumer days.

The 80mm fans only push around 19cfm of air at 12v and the 92mm pushes around 35mm. So at 7v the total airflow is probbaly less than 70cfm.


All psu's get hot and also require cooling. There are so many so-called quiet ones on the market yet most of them are rubbish. There are a few fanless psu's but these have their own specific problems. The quietest fanned psu I have tried is the Nexus3000 so thats what I have. It doesn't really make mcuh of anoise, more of a low whooshing sound thats only really noticeable once you disable the fan then start it up again to see the difference.

Passive cooling

I have heatsinks stuck with thermal glue onto my GPU ram and my motherboard powerfets and also RAM heat spreaders. Given the small amount of airflow that I do have and my respcetable case temperatures, these passive heatsinks should be sufficient.


I found out in my earlier system that rubber washers, fan decouling mountings simply don't work. No to truly isolate fans and other sources of noise from amplifying and transmitting their vibrations and sounds to the case and other components you need to properly decouple, suspend and softmount whenever possible. All my fans are installed onto their Radiator shrouds and Radiators using cushioned sticky tape and then the radiators themselves are mounted to the case using foam and foam gaskets.

In the same way the pumps are mounted on large sponges then stabilised with rubber bands that run through their sides then down under the case where they are tightened using small lengths of, guess what, ......rubber.

In a similar vein, the hard drives and psu are sandwiched with foam to make one large assembly then this is hung from the top of the case using rubber heatshrink. Again, nothing actually touches the main case.




With all 5 fans at 7v they alone are pretty much inaudiable 1 foot away. At the moment they are the least noisy aspect of the system.

The noisiest part is by far the large EHEIM 1250 pump. Not sure if i've damaged it over time but it does seem noisier than it ever was. The smaller 1048 pump is completely inaudible.

The hard drives believe it or not are still a tiny source of noise. Despite the wrapping and their cases and the place at the back of the case they still emit a constant higher pitched whooshing sound that can be heard very late at night if your ear is very near the case. Again, its a sound that is not really identifiable unless you turn them off and compare. I know a chap who has been able to silence a set of barracuda HD's using the aquadrives so its just a case of sourcing some of the acoustic material that he uses to wrap them up in.

The psu does make a low whooshing noise. Its very quiet and certainly we're getting into the realms of perfectionism here but it could be improved upon. A few watercooled psu's exist out there, most noticeably the silentmax prosilence fanless 450W psu which has had its large heatsink replaced with a waterblock. Thing is, in the context of this system the single fan in my psu also acts as the only case exhaust fan that I have; swapping to a watercooled solution would possibly present other problems elsewhere.

Generally though, I'm nitpicking. In the daytime with other ambient noises, (TV, other people, kitchen noises etc..) the computer simply can't be heard. Late at night with very low background noises (boiler upstairs, water pipes, distant hm from kitchen fridge) the computer is still pretty much inaudible from 1-2 feet away. With all background noises completely excluded, i.e. in an environment of complete silence 4am in the morning you can of course hear something. But its certainly not offputting or distracting... you have to concentrate and listen real good if you want to asess it it any way.




Recorded temperatures are not hugely impressive. If I used 2 fans on each rad and high speed high cfm fans at 12v then no doubt temperatures would be quite incredible but thats just really for forum talk. As long as your chip and the rest of your components are kept safely under their maximum advised operating temps by a healthy margin then fine. What really matters is silence.

With all fans at 7v (i.e. ultra silent mode) I get the following figures (bear in mind this fluctuates hugely when the room temperature changes):

cpu: 38c
water*: 28.8 c
ambient air: 22.4c
case: 28.8c
hard drives: 31c
psu heatsink: 42-46c

(* water temp is measured before cooling, i.e. in eth reservoir after it has returned from all the waterblocks.)

under full load (and this is not a real world load but a much harsher torture test run using the prime number generator software Prime95 for 50 tests or around 30 minutes) the cpu temp goes up to around 46c.

In quiet mode with all the 80mm fans at 12v (the computer is still extremely quiet relative to most regular computers) the cpu will idle at around 35c and load is down to 43c.

Remember that motherboards are not very good at acurrately reporting cpu temperatures. The above cpu figures are only a guide and for my own comparisons. In fact, my last motherboard alsomade by Gigabyte recorded everything 2c lower than the current one. Speed, stability under long duration levels of cpu and gpu stress and of course silence are what ultimately make a real difference.




The Jackals Racetrack http://www.jackals-forge.com/lotus 1998 Richard Morris