Keepin' it chill

So the first challenge I am facing in my PC build process is trying to cool my CPU without the stock heat sink/fan that usually comes with the motherboard. This is not an unwelcome challenge as many people have reported that the 40mm fan that comes boxed with my MSI 945GT motherboard is loud. I would like to have a silent system since I'm using a notebook processor in a desktop case.

The board fortunately comes with standard Intel socket 478 heat sink mounting holes so there are plenty of coolers out there that will mount on my board. The low clearance on the Ultra Micro Fly case that I am using means I can't use a tall CPU cooler, but there is enough clearance that I don't have to use a low profile cooler either. A standard sized Pentium 4 cooler should offer a balance of excellent cooling and silent operation. The problem is that the Core Duo processor I am using does not have the integrated heat spreader that Intel desktop chips come packaged with. This allows for thinner laptop designs and makes the chip itself slightly thinner than the Pentium 4 chips that the heat sink is designed for. For my project I will have to compensate for this difference in thickness in order for the heat sink to make contact with the processor die and provide effective cooling.

Some solutions which others have used that I've read about on online forums include:

• Ordering the MSI mobile pad from their online store. This was designed to use mobile AMD cpu's on desktop boards and basically serves as a heat conducting shim to fill the space between the heat sink and the mobile CPU. This retails for $10. Some have been successful using it on Intel mobile cpu's as well, but seems like it would not transfer heat as efficiently as placing the heatsink directly on the processor die.
• One guy sanded down a pre-1972 all copper penny to use as a shim. It's a cheap solution that probably works just as well as the mobile pad, but it still seems that sending heat through 2 layers of thermal paste before reaching the heat sink would not be very effective.

My proposed cheap, easy, and effective solution is to file off the spacers on the bottom of my plastic mounting bracket so the heat sink sits closer to the board and rests on the processor. I will have to keep the spacers at an equal height for the heat sink to sit level across the whole die.

Another thing to note is that the processor can be damaged by all the force of the metal heat sink being concentrated on the small, bare die on the chip. Every stock heat sink I've seen that ships with boards that use mobile chips has a square of felt or foam to help spread the force over the entire chip and protect the die. It also keeps the heatsink level on the chip. I fashioned my own pad out of a piece of thin felt.