3/24/02 - Team Article - By: Brian, Brad, pHaestus and Joe

Water Cooling -(Cont.) By: Joe

Wrap Up and Conclusion to Water Cooling

With all that was on the previous page, you should have a basic grasp on what water cooling is, why it is useful, and what are some of the aspects you need to pay attention to when you design your cooling rig.

There is much more to this topic than could possibly be talked about in one part of an article like this, for more info I would recommend searching ProCooling since many of the articles wrote deal with the extended topics of water cooling in more depth.

Water cooling has come a long way for the PC in the last 4 years, it used to be just one store selling some drilled out block of copper, with a cooler that you put ice in to cool your CPU. Not a really high end or long term solution obviously. Today we have radiators that are being engineered just for PC cooling, water blocks that have as much R+D time in them as some of hardware in our PC's, and designs that are far more safe and robust than ever before.

What's in the future for water-cooling?  My bet is a hybrid Phase change / convection / WaterBlock and Radiator design using a coolant similar to ammonia.  There are some companies already working on this, and it could very well change the cooling scene in the near future!

Air Flow/Air Cooling - By: Brad

This part of the cooling article is going to be broken into a couple of sections; Case cooling with the ATX form factor, CPU, GPU and North bridge cooling. In each section there will be advice and recommendations on what to do, and why. The two major points throughout will be noise and of course cooling.

for this. The 60mm exhaust fan will also aid in removing heat from the VRM's and Northbridge.

With no long PCI cards to get in the way, the graphics card will receive a supply of fresh air from the intake fans. This is quite important, as the GeForce 3 chip produces more heat than several versions of the Pentium 3.With IDE cables or a long PCI card installed however the cooling of the graphics card would be much less effective without this fresh cool air. Also, even though the north bridge has no case fans near it, it is in the path of the airflow from the front fans to the rear fans.

All of what I have described so far is fairly standard, almost all cases have similar configurations. Now lets look at the bad points. Most cases have an 80mm exhaust fan, but this isn't really much at all to try and remove heat from the area where the CPU, GPU, Northbridge and VRM's are. We are seeing a trend to 2x 80mm fans in this area. Typically there is little air flow around the PCI slots. This is only an issue with top end sound cards and gigabit Ethernet cards, which are using an increasing amount of energy. Lian Li cases typically have mounts for some 40mm fans above the PCI slots, which may become an important factor in a few years, the other option is to have a side intake fan blowing over the slots.

The last thing in a case that typically isn't cooled too well is the hard drives. Again, this has never been an issue until recently, with 10,000rpm and 15,000rpm hard drives increasing in popularity. A growing number of cases now have 80mm or larger fans blowing over the hard drives. In particular, the Antec SX series and almost all Lian Li cases feature this.

Now onto what can be done to improve basic case cooling.

This doesn't mean putting an 8000rpm delta at every point where there is a little bit of heat either, careful positioning of fans can be very effective, while producing little noise.

 Instead of having the hard drives mounted above the front intake, why not mount them down the bottom just behind the intake, with the fans blowing over them? This can be easily done by just drilling 2 holes into the bottom of the case and mounting a hard drive directly to those holes. A strip of metal can be used on the top to further support the hard drives. This not only gives more hard drive positions, but it cools them down too. Heat sinks can be added to Hard Drives, but it barely improves cooling and voids the warranty if you glue them on.

The graphics card is hard to cool with air, as it may be only a center meter away from a PCI card, and there is no fan mounts nearby. Options include blowers mounted so that they blow across the surface of the card itself, or a duct can be made to direct the air from an 80mm fan. Another option is mounting an 80mm fan on the side of the case itself, blowing down to the graphics card.

your case, it is possible to have an 80mm fan above the ATX i/o panel blowing in, with a duct aiming it at the CPU, although this might not be practical if it is your only fan in that area. The ducts on the left here are taken from a picture on Caseetc, these are particularly useful for ducts from the side of the case blowing onto the cpu. Many OEM's use a quiet 80mm heat sink with a plastic duct attached to it, it is designed to suck air out through the heatsink. This page here on Dell's support website for one of their dual P4 Xeon systems. This duct has 2x 80mm fans attached to it.  This is a very feasible way to allow a large fan to cool a cpu, without having a huge and heavy heatsink.

Cooling the Northbridge and VRM's is quite an easy task to accomplish, there is the 80mm fan or fans above the ATX i/o panel sucking hot air away, and there is the airflow coming from the CPU fan as well. In the picture I used in the previous page, the air coming out of the CPU Heat sink is directed at the VRM's, while the Northbridge lies in the path of the airflow coming up from the intake fans. Another way to cool these is to mount an intake fan on the side of the case blowing down onto this area, which works very well, bearing in mind the relatively small amount of heat they produce.

Now onto CPU coolers in particular

We have seen huge increases in the size and effectiveness of CPU coolers with every generation of CPU's. From no Heatsinks whatsoever in early 486 days, to fairly small Heatsinks with a fan for early Pentiums, then growing into huge slot Heat sinks with one or two fans, to thin fin high surface area designs in some Heat sinks for today's CPU's. This is to combat the heat produced by the increasing numbers of transistors in the chips, and increased clock speeds.

designs, simply to spread the heat as best possible. Copper has basically twice the Thermal Conductivity of Aluminum, meaning it can spread the heat twice as well as Aluminum. On the other hand, the Pentium 4 has its IHS, which effectively spreads the core out to a 30mm x 33mm area. Which is why many well performing Heatsinks designed for the Pentium 4 are Aluminum, the heat source is over a wider area.

The Future of Heatsinks

The next logical steps are; 80mm thin fin design, basically an extended Thermalright SK-6. Another thing I can see happening is an extended Arkua 7528 Heatsink, designed for 80mm fans, and possibly more fins in the design as well. I doubt we'll see any Heatsinks with a 92mm wide base, unless a new form factor evolves, although Heatsinks with a 92mm wide top are feasible.

Heat sink hybrids using heat pipe technology to get heat spread over a bigger surface of the heatsinks is also the next evolution that has already begun with the few new heat pipe heatsinks that are on the market.

Overall  Wrap up and Links to more info