I know what the Micro ATX means.
I think the smaller board size will not dissipate heat as well.
My point is this. Out of all of the Micro Boards I've seen (using the AM2+
slot), they all have a restriction that is not so widely known. They state
that they can handle AM2+ CPUs but in fact they handle AM2+ processors that
don't draw over 95W. Many people are falling into that trap of building
their computer and later finding out that there burning out the board. The
AMD Athlon 64 X2 6400+ draws 125w and so does the Phenom 9850 Processor.
So the point I was trying to make earlier is that it doesn't matter so much
if the Power Supply has 550W, 650W or 800W of power. These may all be
appropriate power supplies. However, if the motherboard Socket maxes out at
95W.... you better not run the AMD 6400+ or Phenom 9850.
The example below shows a motherboard and cpu, which you would think is
compatible. But they are not.
Example:
Processor:
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103280
Click on specifications. You will see that the Thermal power is 125W