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


View All Comments

  • Anonymous User - Friday, September 19, 2003 - link

    This is a lame arse attempt from Intel in an effort to get everyone to upgrade entire systems.

    Upgrading means :
    (1) profits (PCI-X, new mobos, new CPUs, new bloody everything!)
    (2) they can stick in that Secured Computing crap (La Grande) => control what can be played or viewed. Which means RIAA don't have to sue anymore. It also means goodbye P2P, MP3, Region Free DVD, and all the joys of PC. Prepare to be butt-f*ck by MS in all positions.

    Remember people this is technology consumers can easily reject.

    Simply put, if you don't like it...Don't buy it, don't accept it. There's no one pointing a gun to your head. Intel will see BTX is a failure if no one adopts it.
  • Anonymous User - Friday, September 19, 2003 - link

    Well, hopefully AMD will see the light and not jump on the BTX bandwagon. Gone are the days where Intel had no strong competitors. If AMD simply requests their motherboard manufacturers to stick with the ATX format or modified ATX format with several of the changes suggested in this forum, the BTX format will likely die a quick death. I'm not an AMD fanboy (I have 3 Intel computers) but AMD can force such a BTX resistance in the motherboard industry, I'd support them. Reply
  • Anonymous User - Friday, September 19, 2003 - link

    My opinions:
    - Put the CPU in a separate cooling loop. Otherwise your graphics card is going to be suffering trying to cool itself with air at 35°C
    - As other people have mentioned: standardise the motherboard plugs for reset/power/speaker.
    - Make a standard tiny BTX (femtoBTX?) version, possibly stacked boards with SODIMMs and everything onboard.
  • Anonymous User - Friday, September 19, 2003 - link

    What about cards that pop out during shipping. PCI was bad for this, and AGP was worse. I'm scared that PCI-X, especially 1X will be horrible for this. And #53, the ACR was a gateway to the built-in AC'97 codec, especially for modems, if I'm not mistaken. Reply
  • Anonymous User - Friday, September 19, 2003 - link

    Everyone here seems to have forgotten about the old "Advanced Communications Riser" or ACR, which was supposed to be a cheap solution for putting on modems, audio cards, etc. I believe this PCI Express x 1 is the revival of this horrible standard. Reply
  • Anonymous User - Friday, September 19, 2003 - link

    Hmm, isn't that where the CPU was in the first place (on the old AT boards) before ATX moved it? Reply
  • Anonymous User - Friday, September 19, 2003 - link

    What about the new Apple G5 cooling system? Do something like that for PCs with "thermal zones" to dissipate heat and very very quiet:
  • Anonymous User - Friday, September 19, 2003 - link

    Innovation? My Ar$e!

    This is just a step back to the bad old days of low profile cases & riser cards. Find a pic of an old vtec 486sx and aside form the lack of cooling system *cough* plastic box its the same!

    Swicthing everything to the other side of the mobo is a stinky ploy to get us to buy new new cases.

    How about dual cpu systems, where will the second cpu go, and will it get its own cooling system (lol), or will we get 2BTX cheep at twice the price.

    That and there is no way in hell my 1/2" water cooling setup will fit :|
  • Anonymous User - Friday, September 19, 2003 - link

    It all depends on whether a PCIX1 or PCIX16 card will work in a PCIX32 slot. If they do, just MBs with all PCIX32 slots. Reply
  • jema - Friday, September 19, 2003 - link

    What I dont like is that they are still going for the 'agp scenario' with one PCI express x16 port one the rest x1. Why not make all the card connectors the same size and speed so you can use what ever card you want in any slot? Not everyone will need the gfx card to have the most bandwith in the machine. Reply

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