BTX Form Factor Exposed - A New Way of Building PC's

Weren't we all supposed to be using BTX by now? When this radical form-factor change for motherboards and PC cases was first proposed by Intel in 2003, its introduction was supposed to coincide with the birth of the 'Alderwood' and 'Grantsdale' chipsets we now know as the Intel 915P and 925X.

Instead, the standard took until just recently to get off the ground with manufacturers in Taiwan, resulting in Intel bumping the official introduction of the BTX form factor to their upcoming chipset generation, 'Glenwood' and 'Lakeport.' As far as we know, these chipsets will not be exclusively BTX either, but rather will come in a variety of form-factor 'flavours' to suit the buying public. This is not likely to help Intel's BTX crusade unless its marketers can come up with compelling reasons for consumers to adopt the new standard. With this in mind, PCSTATS is looking into this new form-factor, and what it really has to offer after coming across dozens of BTX motherboards at Computex 2004.

An Introduction to BTX

BTX (Balanced Technology eXtended) is a new personal computer form-factor that has been designed to replace the ATX case and motherboard layouts our computer components are currently built around. At the moment it is an Intel-only proposed standard, as AMD currently has no plans to support the BTX form-factor. There is no reason why it couldn't in the future though

The form-factor of a computer affects the case layout, the positioning of components on the motherboard and the power supply positioning and connections. It allows motherboard, case and power supply manufacturers to know that their products will inter-operate with other parts designed to the same standard.

For example, ATX cases can be designed to accommodate ATX motherboards, since according to the standard, the case manufacturers know exactly where the I/O ports are going to be, and where the PCI expansion ports need to be placed. Likewise, ATX motherboard manufacturers know how many screw holes to place in their boards and where they need to be positioned to fit ATX cases, etc.

BTX, proposed by Intel and recently ratified, makes some fairly radical changes to case and motherboard design in order to provide increased cooling for the components that need it most: the processor, chipset and video card. To put it simply, these components are moved so that they can all be effectively cooled by the airflow passing through the case.

The case itself is modified so that front and rear vents are available to send the required airflow across the motherboard and out the rear of the computer. The rest of the motherboard components have also been shifted to accommodate all this positioning.

Effectively, the BTX form-factor attempts to standardize case cooling so it can provide a steady flow of fresh air that modern components desperately need, while minimizing the amount of noise necessary to deliver it. The motherboard redesign will allow this to happen with a minimum of active cooling, with a single 'thermal module' both cooling the processor and creating the stream of air that will cool the other components.

Let's run through the actual changes that the BTX standard makes to traditional ATX components, as there are a few other developments to consider.

BTX Changes: Thermal Solutions and Motherboard

The most obvious change to the motherboard is how the heatsink interfaces with it. The orientation of the processor heatsink has been altered from the standard downward facing fan/heatsink design to one that blows air through from side-to-side. Instead of the comforting, fan-topped hunk of aluminum or copper we've all become familiar with, BTX introduces something completely new, the 'thermal module.' The so called thermal module consists of the heatsink, fan, and fan duct.

Dell, to name just one manufacturer, has long been using air ducts to reduce noise from inside the PC, while at the same time cooling its PC's internal components just as effectively. The thermal module takes this one step further. Combining a single large fan, a heatsink for the processor and some form of ducting to guide airflow, the thermal module will be the key for effective cooling of BTX systems.