Quiet, Powerful Computing
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"Is that a 1966 Ford Mustang radiator next to your computer, or are you just happy to see me?"
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I am the biggest nerd you know
Discuss this build on Silent PC Review here
In a nutshell: computers generate heat. More power usually means more heat. Getting rid of that heat usually creates noise. But it doesn't have to.
I do a lot of heavy computing, so I need a fast machine. I also do recording and audio work, so I want a machine that is quiet. Getting both of these is not always easy but I think I succeeded.
My old computer was noisy as hell. The case was so cheap, the side panels left a big gap. The fans were loud, it vibrated like crazy, and it was cramped and dirty. This upgrade was a long time coming, and I wanted to do everything right.
All computer components generate heat. Many modern components generate so much heat that they require cooling, or else they will overheat and fail. In very rough order of heat output, here are the main components that must be kept cool:
Typically, there are three ways to cool components: fans (active air cooling); heatsinks (passive air cooling); and watercooling.
Fans are by far the most common cooling. Often there is a fan for the CPU, GPU, Northbridge, and one or more case fans for overall airflow. Unfortunately most fans are noisy, especially the smaller component fans.
Heatsinks are simply finned metal (aluminum or copper) blocks, attached to a component via thermally transmissive paste. The heat moves from the chip to the heatsink, and is then convected into the air. For small chips this works quite well with even minimal airflow, but for the primary components a fan is often still required.
Watercooling is more complicated; although it is becoming more common it is still fairly esoteric. There are many sites with extensive background, but briefly: heat is absorbed into water moving through a loop, then carried away to a radiator and dispersed. Typical components include:
Although potentially silent, watercooling still involves moving parts: the pump and fans. Usually, radiators still require fans for sufficient convection. But if the radiator is large enough... Pump choice is also important.
One final source of noise is the mechanical action of the hard drives (aside from any cooling needs).
The case is super-important, as it determines fan size and placement, airflow, etc. I went with a cheap case before; this time I chose the very high-end Lian-Li PC-V2100.
First of all, this case is huge! It really surprises you the first time you see it. Keep in mind, it's actually deeper than it is high. Overall, I could not be more pleased with the case -- the build quality is superb, everything fits perfectly, most frequent screws are thumbscrews, and most pieces are screwed, not riveted (making it easy to remove unneeded parts).
The case is aluminum, which has a reputation for being noisier than steel. It's thinner, so it transmits more sound, and it also vibrates more readily. I intend to minimize component noise so this is not an issue. Aluminum is also a lot easier to cut.
The case comes with "soundproofing" foam on the side panels, parts of the front, and the ceiling (but not the floor or middle divider). Although I don't suppose it can hurt, the foam is very thin and light. Acoustipak is much more effective, so I added it at strategic spots (left over from my last build).
There is also a door, to keep noise from escaping out the front. The door seals with a rubber gasket, and is very effective. It also looks nice.
Airflow could be a problem. There are some small intakes on the floor, a 120mm exhaust for the main chamber, and the PSU exhaust of course. A 120mm intake pushes air over the hard drives. With watercooling, airflow is much less important so this was not an issue for me.
The front fan has a removable filter. The fan mounts on rubber grommets that actually do seem soft enough to damp vibrations. There is also some rubber around the mounting holes on the case itself.
There's soundproofing foam on the exhaust duct! Again, the foam is pretty flimsy, but it demonstrates that this case is very finished with many nice details.
For some dumb reason, there's no reset switch. So I drilled a 1/4" hole for a momentary push switch. When I get around to it, I'll replace it with a nicer-looking silver toggle switch.
I also took out the second set of hard drive rails, to make a larger middle chamber.
A drawer! How cheesy is that!? Actually though, with no desk drawers it comes in really handy for misc. screws and guitar picks and such. (This didn't come with the case, it's a Thermaltake addon).
Try not to lose the screws! This case comes with over 200 screws.
Of course the centerpiece is my beautiful car radiator. I got this puppy off of E-bay from a 1966 Ford Mustang V6 automatic. (You could use a foreign radiator, if you hate America. You don't hate America--do you?) I took it to Rex Radiator, had them clean it, paint it and solder smaller barbs on. Since the core is all copper, like my blocks, there won't be any issues with galvanic corrosion.
You can buy commercial passive radiators, but they tend to be underpowered or overpriced, or both. This thing was cheap and can handle more CPUs than I could ever afford. Perhaps it doesn't look quite as nice, though I think it has a certain appeal. At any rate I put it in a little wooden enclosure, so it's not very visible anyway.
I also used a number of Eheim quick disconnects (their 12mm double-taps). Get these!! Each side has a ball valve that can be shut. The two sides can then be pulled apart with minimal fluid loss. When open, the valves create no flow restriction (a smooth 10mm ID bore). Using these liberally makes watercooling far more effortless. To pass them through the middle divider, I used a Greenlee 1" hole punch, the perfect size. I also fit one to the outlet of the pump (the intake is too large to fit one directly). I used enough disconnects so that I could separate out the pump, the motherboard/video card, and of course the external radiator; a total of four.
My loop is powered by an Eheim 1250 AC-powered pump. This pump is pretty quiet, but vibrates like holy hell. It is absolutely necessary to completely suspend the pump via elastic bands.
Because the pump is AC-powered, I used a relay card from Mitron Interlink. This allows the pump to be turned on or off automatically with the computer's power supply. There is also a passthrough switch to allow running the pump with the computer off, helpful for filling and bleeding. Rather than cutting the pump cord to splice the wires (voiding the pump warranty), I just used an extension cord. A final note: the more common Criticool Powerplant draws power through the PCI slot, potentially dangerous when mixed with AC power. This card uses a standard molex, which is safer. Also, even though it uses a two-prong cord, it does in fact ground the pump to the computer case.
I used Dangerden Maze4 CPU and GPU blocks. I used a mixture of Tygon and Clearflex tubing, though I should have just bought more Tygon. Everything is 1/2" ID, 3/4" OD. In retrospect, this size is a pain in the butt. Using 7/16" ID tubing would have been smarter. I also should have used the softer Tygon R1000 tubing at the pump, to minimize vibrations. Vibrations will travel a long way down the more common R3603 tubing I'm using. I used some heavy vinyl fabric and wrapped it around the tubing to absorb some vibration. The coolant is a mixture of 90% distilled water, 10% Zerex racing super coolant.
Before I put the GPU block on, I attached a thermal probe with thermal adhesive.
I still need some airflow for secondary components. I removed the stock ADDA fans and replaced them with two Nexus Real Quiet 120mm fans (black-and-white version). They are almost silent even at full speed. I mounted them using Acousti Products rubber fan mounts, to avoid transmitting vibrations to the case. (I've heard, but can't confirm, that these mounts are better than the lookalikes). Using these mounts requires cutting the fan ribs, detailed here.
I control the fan speeds with an Aerogate CoolerMaster III. For $10, you get control of four fans, and four temperature sensors. I wanted manual (not temp-based) fan control. I dropped them from the stock 1100rpm to about 900rpm, and they're inaudible from 8 inches (through the case).
Instead of a Northbridge fan I use a Zalman heatsink. I put Nexus heatspreaders on the RAM (they are very shiny in person and look great!) I used Microcool aluminum heatsinks on the MOSFETs and PLLs. I used Swiftech MC14 copper sinks for the video RAM. All the sinks were attached with a 1-to-1 mixture of Arctic Silver 5 thermal paste and Arctic Silver Thermal Adhesive.
Though it doesn't show up well, the RAM heatspreaders are very shiny and look awesome!
The Northbridge does need cooling, and you should probably use sinks for video RAM when watercooling the GPU. Many people might feel the remaining heatsinks are unnecessary, but they are cheap and can't hurt. The MOSFETs do get quite hot, so the sinks are probably helpful in this low-airflow scenario.
The power supply is a Seasonic S12 600W Rev. A2, with a very quiet built-in fan. I cannot hear it at all unless I'm within 8 inches or so.
There are three considerations for quiet hard drives: vibration noise, seek noise, and heat. Vibration noise can be solved with decoupling; seek noise by enclosures. But both those methods tend to raise the temps, unless you specifically address that. The Lian-li uses plastic hard drive rails that it claims reduce vibrations. They are very hard and I doubt they are effective. But, I am using them for now. I think the extra Acoustipak helps both forms of noise. They are very very quiet, but if I ever feel like doing better it will be easy to change to a different solution.
This system is almost silent. The fans are inaudible, the hard drives are very quiet, and the case makes no vibration noise (though you can feel a very slight vibration if you touch it). Unfortunately, the pump is slightly damaged and makes some light chattering noise. In the daytime, this is inaudible over ambient. At night, it is very faint but detectable. I will either repair the pump or replace it with an Eheim 1048 in series with a Dangerden DC-powered pump. Again - the damaged pump is the only detectable noise.
Temperatures are OK, not great. Case temp is usually around 38, CPU between 42 and 48. The temp probe on the GPU reads about 40-46. The PSU fan spins around 750rpm, so its temps are fine. Hard drive temps are about 40. All of these are fine but could be better. (The room gets close to 30, which doesn't help).
The case temps result from the low airflow. The CPU temps I blame on the block (which I feel I didn't seat particularly well) and the pump's low-ish pressure than the passive radiator. A new pump might help, and a CPU upgrade means new blocks anyway. If absolutely necessary, I could put two undervolted Nexus fans on the radiator, and still be effectively silent. (Edit: I did put two Nexus fans over the radiator, with no impact, proving that the bottleneck is elsewhere. I really feel it's just a bad block seating).
The case also looks great. There a a lot of wires inside, and I probably could have dressed them better, but the case is still quite easy to work in. Maybe I should add some lights and a window! I built a nice little enclosure for the radiator so it's not just sitting in the middle of my apartment.
This all might seem like overkill, but I wanted to plan ahead. My next upgrade will be to at least a dual-Opteron setup. I want cooling that can handle cutting-edge systems.