Noise and PSUs
Noise
Thermal testing is outside the remit of this article for many reasons (the main one being I'm not convinced a thermal representation of microBTX is relevant at the time of writing), although Purav does do the testing for Anandtech on the same reference hardware. Take from it what you will.However, the aural aspect is worth considering, even in isolation. The reference evaluation platform for BTX as outlined on the previous page is quiet, but not any more so than a well thought out ATX solution is. Indeed, with my usual hard disk and optical drive installed into the B300, I'm hard pressed to determine much difference between the BTX B300 and its Type 1 thermal module, and my existing ATX chassis and cooler. My usual chassis is an Akasa Eclipse-62 and I'm using the AMD reference cooler for an FX-55 processor, on an FX-53, with Cool and Quiet enabled in the mainboard's BIOS. The two 120mm fans in the Eclipse are very quiet and my hard disk makes the bulk of the noise in the system.
Placing the D915GMH inside the B300 with the supplied Pentium 4 550, with its thermally adjusting fan speed (which can't be shut off it seems), the fluctuating temperature of the processor causes the fan speed to adjust at all times, up and down, and the pitch changes are distracting, if not loud at all in terms of decibels. Counter that to the FX-55 reference cooler which changes speed too, but whos pitch changes of the noise generated are far less discernible to my ears.
With coolers ever quieter these days, it's the pitch changes that your ear picks up and your brain reacts to, rather than deafening levels of noise that you hear. In that respect, the fan on the Type 1 BTX Thermal Module isn't any better than anything you'll get on a good 'ATX' air cooler.
In response, Intel are keen to note that acoustics weren't at the very top of the list in the early days of BTX and the creation of the first Thermal Module designs. However with that out of the way, acoustics are absolutely at the top of their focus list for BTX, for certain divisions and groups within Intel.
With governments basing entire tenders on the noise of PC systems today, it's something they've got on their radar to tackle. So the noise of the reference thermal module, while quiet in absolute terms, isn't quite there yet in the fan design in terms of pitch change. But it should be in the future.
The Power Supply Question
Before I move on to some overall thoughts, there remains the question of power supply to get through. Revisions of the ATX power supply standard have evolved over time to incorporate advances in technology. So a bang up to date power supply today will get you 24-pin EATX main power connector, some SATA power connectors, ATX12 (P4) and P4+ connectors, possibly PCI Express graphics connectors and split 12V rails for CPU and the rest of your system.Generally, an ATX power supply won't be suited to new placement in an BTX chassis due to fan placement. Recent ATX PSU designs from the likes of Tagan are BTX compatible in the right chassis and provide all the mainboard and peripheral connectors needed for powering a board like the D915GMH, but for many it also means a PSU upgrade. They'll more often than not come with any new BTX chassis, but it's something else to consider and something else that changes along with the mainboard, chassis' and coolers.
