Balanced Technology eXtended (BTX)

Aron Schatz
June 1, 2005
Balanced Technology eXtended (BTX)
Perhaps you've heard of BTX already, but how many of us have seen or used it? BTX is more than just another form factor. BTX hopes to make computers smaller and quieter by changing the component layout on the motherboard. This article will serve as a primer for BTX as it stands today.

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When Intel released the BTX standard in 2003, ATX was going stronger then ever. We are now at a point of where ATX is hitting a limit on thermal design. Ducting can only do so much for us. It is time to move on to a new and better standard. Enter BTX...

Why BTX?

The first question we should answer is why ATX (Advanced Technology eXtended)? The ATX form factor was originally introduced in August 1995 by Intel, and was widely adopted in 1996 by most motherboard, power supply, and chassis manufacturers. Everyone that has touched a computer within the last 10 years has seen an ATX motherboard. I'm sure the computer you are using right now probably contains one. The ATX standard brought out a standard back panel for I/O and a new power supply standard (connectors and dimensions). The standard ATX plug we see today is an example of the standard. There have been updates to the standard (ATX12V and others), but everything has generally remained compatible, pin wise, with each other. Since ATX is 10 years old, it was made when computing did not put out as much heat as the newer generation Pentiums and Athlon do. Intel released the BTX specifications in 2003 to combat the heat problem facing modern computer systems. Along with a change in form factor, changes in the power supply and connectors are also introduced. BTX power actually is the same as the ATX12V 2.x with the PCI Express connector (optional). You can read an excellent article on different standards of power supplies by going here:

There are other improvements that BTX offers over its older brother. The BTX standard has three sizes of boards; The standard, the micro and the pico. They are listed in order of their size, biggest to smallest. The three layouts all differ in the amount of expansion slots are available. The same core layout exists on each size board. The other thing that makes BTX different from ATX is that BTX allows for a heatsink of 900g to be placed on the CPU. It is deemed the thermal module as you'll see soon. The module cools the entire system, not just the CPU.

The Thermal Module:

530J BTX

Since BTX is relatively new, I only have what I bought from the ICC that I went to earlier in the month. The new Intel boxed CPUs are labeled for BTX boards as the heatsink is different for BTX over ATX. I actually have a 530J BTX CPU.


It is rather big compared to a normal size heatsink. This thermal module is a type 1. There is a type 2 thermal module that is smaller and is designed for pico sized boards (as it cools less than the type 1).

HSF Front HSF Back HSF & CPU

The sheer size of the module compared to the CPU is amazing. There are a few things here that make this possible. The case and the motherboard both have mounts to support the weight of the module. Since this is built into the BTX standard, no weird type of mounting holes will be needed (as some boards had for rather large heatsinks).

The BTX motherboard:


I have in my possession a boxed D915GMH which is a BTX board. I was pleasantly surprised that the board layout is very well thought out. All the components are inline for efficient cooling. Before anyone starts mocking Intel that the reason the BTX standard was made was for Prescott, just look at the standard for what it is, a terrific evolution from ATX.

BTX Board Motherboard 2

The layout of the motherboard has changed dramatically from ATX. First, you'll notice that the CPU is now located at the far left of the board and turned 45 degrees, as are the north and southbridges. This is done to increase the cooling inline with the airflow from the thermal module. Directly in line to the right is the northbridge (and the supporting components) and the southbridge. The memory is situated at the top of the board, out of the way of anything to block airflow. The power and cabling are turned parallel to the airflow so it doesn't get hampered as it did with ATX. Here is a thermal diagram of a typical BTX system would look like.

Motherboard Airflow Air Flow Diagram

The thermal module sucks in the cool air from the outside and then it flows over the CPU and then to the other parts of the case. ATX had the air being sucked in from the front and the CPU was the last thing cooled. In BTX, the CPU is the first to receive fresh air and it is then filtered to the other parts of the case. This is a big improvement over ATX since it not only cools more efficiently, it does so with less fans.


There are only a handful of Intel CPUs that are boxed with the BTX thermal solution and even less motherboards. The D915GMH is around $115 at Newegg and there are a bunch of different CPUs to choose from. Since BTX is relatively new, it is best to wait for the technology to mature before diving into it head first. ATX will be around for quite some time during the transition. You'll have enough time to ease into the new form factor. In a few months, more and more choices will be available and we will come back to the technology in other article when there are more boards to choose from.

Thanks for reading. Make sure you stop by the forums: »


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