Three different BTX sizes

Much like the multiple sizes of ATX (micro, flex, etc...), the BTX form factor allows for multiple versions of the form factor. In terms of motherboard sizes, there are three types: picoBTX, microBTX and regular BTX.

Although the board pictures below are obviously not to scale (the BTX board is clearly larger than the picoBTX board), the idea is to show you the difference in expansion slots between the boards.

8.0" x 10.5"
up to 10.4" x 10.5"
up to 12.8" x 10.5"

The picoBTX standard can support either one or two expansion slots and has four mounting holes. PicoBTX cases will probably have one 3.5" and one 5.25" drive bay.

The microBTX standard, which most are expecting to be the more popular of the three, has support for four expansion slots and has seven mounting holes. MicroBTX cases will feature one 3.5" bay and up to two 5.25" bays.

Finally we have the regular sized BTX, supporting up to a full 7 expansion slots and mounts to the case using 10 mounting screws. Regular BTX cases will be more like the mid-tower ATX cases we have today, supporting 3+ 3.5" bays and 3+ 5.25" bays.

The BTX standard allows for two case heights - Type I and Type II. Type I cases are 3.98" in height and can use normal expansion cards, while Type II cases are for small form factor designs and are 3.0" in height. Expansion cards would either use risers or be low profile in a Type II case.


The rear of a microBTX case, you can see the circular heatsink in the thermal module.

BTX - The Basics Graphics in BTX
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  • Atropine - Thursday, September 18, 2003 - link

    Intersting changes coming our way, just don't know how well it will be accepted by the PC Enthusiast Community.....from the looks of these comments, not very well!
  • Anonymous User - Thursday, September 18, 2003 - link

    DAMN its ugly.
    Can see the market for case windows dropping substantially
  • Anonymous User - Thursday, September 18, 2003 - link

    #19,

    Better take another look at that thermal picture. As far as I can tell that is an air intake!

    Usually a darker color depicts a lower temperature. Now look at the area surrounding the CPU. Directly above the CPU you can see the color streaking from the heatsink.

    Even more telling is the color streaking up from the graphics card.

    I also have a bad feeling about heating the computer in this way. But Intel has done this before. In the original ATX specifications the CPU was to be cooled by a passive heatsink, being cooled by the air being blown in through the PSU. To facilitate this the CPU was located directly below the PSU, and the PSU were to be equipped with a fan mounted on the bottom, blowing air down.

    In retrospect it doesn't seem like a very good solution, and it never was. The ATX specification was quickly revised, but not before the major OEM manufactures had pumped out many thousand computers with the original configuration.

    This BTX standard doesn't appear to be a good design, and it will be interesting to see if it can succeed. I don't think it deserves to, not in it's current incarnation, but I'll reserve the right to change my mind once I get to play with one.
  • Anonymous User - Thursday, September 18, 2003 - link

    "Virtually no computer systems have 'air intake fans'."

    Put down the crack pipe. Intake fans are pretty common.
  • Anonymous User - Thursday, September 18, 2003 - link

    I'll be mad, too. I've got a box full of Model M keyboards, in case the two I'm using now ever go bad.

    Best keyboard of all time == IBM Model M.
  • Anonymous User - Thursday, September 18, 2003 - link

    A LOT of people still use parrallel ports for printers. I'm a comp. tech, and I see them ALL the time.

    The serial ports... they're hardly used at all, but when you need them, you NEED them.
  • Anonymous User - Thursday, September 18, 2003 - link

    I still can't believe noise is that much of a problem to people. Does it really bother people that much when they hear a fan spinning?
  • Icewind - Thursday, September 18, 2003 - link

    What the hell is with the changing of position on the open side of the case is beyond me, and I find that new PCI express power requirments a total joke. My gawd, were gonna need 1000W PSU's at this rate. I love case modding and such, but this seems like a joke to me personally, i'll keep my modded Antec 1000AMG "Blue Fantasy" for a long time to come...

    http://www.3dbistro.com/ftp/icewind/fantasy4.jpg
  • Anonymous User - Thursday, September 18, 2003 - link

    Duh. Geez, get it right. That's *not* an air intake fan by the CPU, that's the exhaust fan. Just take a look at your own thermal picture. The CPU is the last thing to get the cool air, as it should be, otherwise all your components would just be heated up by the CPU. Grade school thermo tells you the way to efficiently cool something like this is to exhaust the hot air, not blow in cool air. Virtually no computer systems have "air intake fans."
  • Anonymous User - Thursday, September 18, 2003 - link

    Can u put a BTX and an ATX picture side by side to compare the difference? I'm wondering also if that one picture is backwards

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