Improving System Cooling Part 2 - Keeping the North Bridge Cool How to install North Bridge/MCH/GMCH coolers
Improving System Cooling Part 2 - Keeping
the North Bridge Cool
How to install North Bridge/MCH/GMCH coolers
Whether its chilly winter or balmy spring outside, theres only one season inside your computer: summer at high noon in the desert.
Faster processor and memory clock speeds increase heat throughout the computer. However, although processors are protected by heatsinks (usually equipped with fans) and high-speed DDR SDRAM memory modules increasingly sport the same heat spreaders originally developed for use with fast RDRAM modules, the rest of your motherboard might not be as well protected.
Consider the North Bridge chip (also called the Memory Controller hub or Graphics/Memory Controller hub). It carries high-speed data traffic between the processor and memory, AGP video and the rest of the computer. What happens if it overheats? Unlike an overheated processor or memory module which can be replaced if it fails, the North Bridge chip is an integral part of the motherboard. If it fails, it takes down the entire motherboard.
Thus, its little wonder that most recent motherboards now feature onboard passive or active cooling of the North Bridge chip. If your motherboard doesnt, or if the North Bridge cooling fan starts to fail (check the hardware monitor in your system BIOS for fan speeds or listen to your system for unusual noises coming from the fan), its time to install a new one.
The North Bridge Chip and Cooling Kit
Figure 1 shows the North Bridge chip on a motherboard which uses a VIA Technologies chipset. A cooling fan attached to this chip has failed and has already been removed.
Figure 1 The North Bridge chip and fan connection after the old North Bridge cooling fan was removed.
What does a North Bridge chip cooling kit look like? Figure 2 shows the contents of a typical Vantec Thermal Solutions cooling kit.
Figure 2 Vantec Thermal Solutions cooling kit has both passive and active coolers for the North Bridge chip as well as a passive cooler for the smaller (and cooler-running) South Bridge chip.
This particular cooling kit uses a ball-bearing fan, which is a bit more expensive but quieter and longer-lasting than a sleeve-bearing fan.
Securing a Passive or Active Heatsink
There are two ways to attach a chip cooler to the North or South Bridge chip:
- thermal tape
- mounting clips or pushpins
Thermal tape can be easier to work with (its basically a double-stick tape with thermal-transfer properties) than clips or pushpins, but it should be used only on motherboards that dont have holes for push pins or clips. One potential hazard of thermal tape is the loss of all cooling if the tape dries out and the cooler slips off the North Bridge chip. Clips and pushpins provide a more secure way to hold the cooling fan in place.
Installing a North Bridge Cooler
To install a North Bridge cooler:
1. Shut down the system and unplug it.
2. Take the ESD (electrostatic discharge) precautions discussed in Chapter 22 of Upgrading and Repairing PCs.
3. Open the system and remove the existing North Bridge cooler (if any)
4. Determine if you can use the active (powered fan) cooler. Its easiest if the motherboard has a nearby connector for power and fan speed monitoring. If not, use the power adapter to pull power from the power supply, or piggyback on a drives power connector.
5. Carefully clean the surface of the North Bridge chip to remove any residue left from the previous cooler.
6. If the cooler will be clipped into place, put a small amount of thermal paste over the center of the North Bridge chip, as shown in Figure 3. If the cooler uses thermal tape, refer to the instructions for installing the South Bridge cooler in place of steps 6-8, then return to these instructions and follow step 9.
Figure 3 Applying thermal grease to the North Bridge chip before installing the cooler.
7. Depending upon the exact design of the cooler and the mounting clips, you might want to push them into place on the North Bridge before you install the North Bridge cooler. Because the mounting clip holes on the cooler being installing dont match up to the mounting holes on the motherboard, thats the approach being used here.
8. Push the North Bridge cooler into place and secure it with the mounting clips. You might find it useful to have a ballpoint pen or needle-nose pliers to manipulate the clips as needed to secure the fan.
9. Plug the fan into the motherboard or the power supply.
Installing a South Bridge Cooler
The South Bridge chip (see Figure 4) typically handles lower-speed data than the North Bridge and thus is less likely to overheat. However, if the North Bridge cooler kit you purchase also has a South Bridge cooler, theres no reason not to install it.
Figure 4 The North Bridge chip cooler (top) after installation, compared to the South Bridge chip (bottom).
To install the South Bridge cooler:
1. Carefully remove any residue or dust from the surface of the South Bridge chip and the bottom (flat side) of the cooler.
2. Peel off one side of the protective cover over the thermal tape and attach it to the bottom of the cooler.
3. Peel off the other side of the protective cover over the thermal tape on the bottom of the cooler.
4. Line up the cooler carefully with the South Bridge chip and slowly push it into place.
5. After the South Bridge cooler is installed, your motherboard should resemble the one shown in Figure
Figure 5 The North Bridge chip cooler (top) and South Bridge chip cooler (bottom) after installation.
At a cost of less than $15, a North Bridge cooling kit is excellent insurance against motherboard failure caused by overheating this vital component. As a bonus, typical kits also protect the South Bridge chip, providing an extra margin of safety.
For Further Research
Vantec USAs website is located at
Zalman Tech Co. Ltd also makes great heatsinks and has a Flash
animation on their installation.
See www.zalmantech.com for details.
Intel offer specific guidance on thermal solutions for its 875P (Canterwood) http://www.intel.com/design/chipsets/designex/252528.htm and 865-series (Springdale) http://www.intel.com/design/chipsets/designex/252519.htm chipsets at the websites listed. These are also helpful for understanding the thermal issues involved with any recent motherboard chipset.
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