It seems every PC manufacturer is all about quiet these days. It's what the consumer wants. A truly silent PC is the "holy grail" of the computer industry today because it integrates beter into the home and users suffer less stress from a quiet computer than a whiny, noisy PC. Some manufacturers have successfully built PCs that use convection cooling (the G4 Cube and iMacs) but this is even harder than ever for manufacturers to do because processors are putting out more and more heat, and convection cooling seems nearly impossible these days. (It would be possible, but your entire PC would be dominated by a giant heatsink.) Manufacturers like Dell have found that the most cost-effective way to provide near-silence is the use of thermally-controlled fans that only speed up when they are necessary. Unfortunately, PC ehthusiasts and owners of custom PCs have a tougher time tackling the noise problem because super-high-performance components are used, so a bit more creativity is necessary in a silent cooling scheme for a high-performance enthusiast PC. This is my plan for anyone building a new PC to finally achieve Dell-like silence from their computer. It uses Zalman components and atleast a single Vantec ThermoFlow 80mm case fan.
We will start at the source of most annoying computer noise: the CPU fan. First of all, choose a motherboard with a passive chipset heatsink. This is important to eliminate another fan from your system and further reduce unwanted sound. If you already have a motherboard, and it uses a chipset fan that is attached by plastic pegs, get a Zalman passive Northbridge heatsink and use Arctic Silver III for best thermal transfer. Buy a Zalman CNPS "Flower" cooler and some Arctic Silver III thermal goo. Install the Flower and/or the chipset cooler. Once you are done mounting these products, then measure the dimensions of the Flower. Using the measurements you make, build a cardboard tunnel that leads to a shroud sized to fit around the Flower with minimal extra air leakage around the CPU. We will not use the Zalman-supplied 92mm fan, but rather we will use this tunnel to draw air across the Flower. One end of this tunnel will be a shroud which fits (with close tolerances--hence the extra measurements) around your Flower cooler, and the other end of the tunnel will fit around your rear case fan. (We'll talk about case fan selection later.) Because this is a negative-pressure (sucking) configuration, there must be very little air leakage around the "Flower" or the rear fan. I recommend using duct tape for a sure, tight seal around your case fan and and any leaks in the cardboard shroud itself. Shoebox cardboard will be good for this, but if your cardboard is too thick, it will be too hard to work with. Don't duct-tape anything to the Flower, but rather make sure you attach it sturdily to your fan. Also, make sure you allow plenty of space for air to enter around the base of the flower. That is, only let the shroud come within 1" of the motherboard.
For your rear fan, I recommend you buy a Vantec Thermoflow case fan (80mm and up -- no smaller than 80mm) or some other thermal-controlled case fan (Enermax, Antec, etc.) to attach to the rear of your case because the ThermoFlow is thermally-controlled. If your case has restrictive fan grilles in the back (on what will become the Flower's exhaust fan), use nippers to cut them off. Then you can use hamburger-style fan grilles to guard the rear fan. If your case has space for two fans in the rear, then get 2 ThermoFlow case fans and make it so the cardboard shroud uses the airflow from both of them. The more rear fans you can connect to the Zalman Flower, the better your performance will be, and the slower the fans can run, making less noise even at higher loads.
If your power supply is not an Enermax or Antec dual-fan type, get an Antec True-series power supply that uses the Low Noise system. The Antec's fans run slower than the Enermax. This will lessen the power supply's contribution to case noise.
Then get a Zalman VGA heatpipe for your video card. Run it fanless, as it was intended to be. The ZM80-HP uses a heatpipe to transfer heat from the GPU on the VGA card's underside to a gigantic passive heatsink on top. This should be able to even handle Radeon 9700s and higher-performance GPUs that may soon be released. Use the leftover Arctic Silver 3 thermal goo from the Flower to ensure efficient thermal transfer from the GPU to the heat pipe.
A good brand of hard drive to choose is Seagate. Specifically, choose the Barracuda IV drives which use Fluid Bearings as a standard feature. They last long and are practically the best hard drives in the business. They are also the quietest. If you have a case that uses case fans in the drive cages to cool the hard drives, then get a YS-Tech adjustable fan and run it on its very lowest setting (while checking to see that it has enough voltage that it will still start when you turn on your PC -- fans require more voltage to start than they do to run). However, only do this if your hard drives feel warm to the touch when cooled passively.
This computer system should run very quietly and yet be able to accomodate even very fast processors like the Athlon XP's, high-performance chipsets like the VIA KT400, and very fast graphics cards, like the GeForce 4 ti 4600 and the ATi Radeon 9700.
Plan from the start to have a quiet computer! If you buy these things as part of a new computer, you should be most impressed. If you have money to spend, then you can add these things after the initial purchase. Please, however, don't try this unless you have a very, very good idea of what you are doing and how air moves, otherwise you may lose your processor due to faulty engineering of the CPU fan tunnel and shroud.
While I'm here talking, I'd like to see Zalman make a gigantic heat-pipe unit for CPUs that allow full passive, fanless cooling. Maybe they could build it to be used in conjunction with a dual-fan design power supply, with the bottom fan drawing air through the heatsink of the heatpipe.
We will start at the source of most annoying computer noise: the CPU fan. First of all, choose a motherboard with a passive chipset heatsink. This is important to eliminate another fan from your system and further reduce unwanted sound. If you already have a motherboard, and it uses a chipset fan that is attached by plastic pegs, get a Zalman passive Northbridge heatsink and use Arctic Silver III for best thermal transfer. Buy a Zalman CNPS "Flower" cooler and some Arctic Silver III thermal goo. Install the Flower and/or the chipset cooler. Once you are done mounting these products, then measure the dimensions of the Flower. Using the measurements you make, build a cardboard tunnel that leads to a shroud sized to fit around the Flower with minimal extra air leakage around the CPU. We will not use the Zalman-supplied 92mm fan, but rather we will use this tunnel to draw air across the Flower. One end of this tunnel will be a shroud which fits (with close tolerances--hence the extra measurements) around your Flower cooler, and the other end of the tunnel will fit around your rear case fan. (We'll talk about case fan selection later.) Because this is a negative-pressure (sucking) configuration, there must be very little air leakage around the "Flower" or the rear fan. I recommend using duct tape for a sure, tight seal around your case fan and and any leaks in the cardboard shroud itself. Shoebox cardboard will be good for this, but if your cardboard is too thick, it will be too hard to work with. Don't duct-tape anything to the Flower, but rather make sure you attach it sturdily to your fan. Also, make sure you allow plenty of space for air to enter around the base of the flower. That is, only let the shroud come within 1" of the motherboard.
For your rear fan, I recommend you buy a Vantec Thermoflow case fan (80mm and up -- no smaller than 80mm) or some other thermal-controlled case fan (Enermax, Antec, etc.) to attach to the rear of your case because the ThermoFlow is thermally-controlled. If your case has restrictive fan grilles in the back (on what will become the Flower's exhaust fan), use nippers to cut them off. Then you can use hamburger-style fan grilles to guard the rear fan. If your case has space for two fans in the rear, then get 2 ThermoFlow case fans and make it so the cardboard shroud uses the airflow from both of them. The more rear fans you can connect to the Zalman Flower, the better your performance will be, and the slower the fans can run, making less noise even at higher loads.
If your power supply is not an Enermax or Antec dual-fan type, get an Antec True-series power supply that uses the Low Noise system. The Antec's fans run slower than the Enermax. This will lessen the power supply's contribution to case noise.
Then get a Zalman VGA heatpipe for your video card. Run it fanless, as it was intended to be. The ZM80-HP uses a heatpipe to transfer heat from the GPU on the VGA card's underside to a gigantic passive heatsink on top. This should be able to even handle Radeon 9700s and higher-performance GPUs that may soon be released. Use the leftover Arctic Silver 3 thermal goo from the Flower to ensure efficient thermal transfer from the GPU to the heat pipe.
A good brand of hard drive to choose is Seagate. Specifically, choose the Barracuda IV drives which use Fluid Bearings as a standard feature. They last long and are practically the best hard drives in the business. They are also the quietest. If you have a case that uses case fans in the drive cages to cool the hard drives, then get a YS-Tech adjustable fan and run it on its very lowest setting (while checking to see that it has enough voltage that it will still start when you turn on your PC -- fans require more voltage to start than they do to run). However, only do this if your hard drives feel warm to the touch when cooled passively.
This computer system should run very quietly and yet be able to accomodate even very fast processors like the Athlon XP's, high-performance chipsets like the VIA KT400, and very fast graphics cards, like the GeForce 4 ti 4600 and the ATi Radeon 9700.
Plan from the start to have a quiet computer! If you buy these things as part of a new computer, you should be most impressed. If you have money to spend, then you can add these things after the initial purchase. Please, however, don't try this unless you have a very, very good idea of what you are doing and how air moves, otherwise you may lose your processor due to faulty engineering of the CPU fan tunnel and shroud.
While I'm here talking, I'd like to see Zalman make a gigantic heat-pipe unit for CPUs that allow full passive, fanless cooling. Maybe they could build it to be used in conjunction with a dual-fan design power supply, with the bottom fan drawing air through the heatsink of the heatpipe.