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

    Yeah, this new thing is going to be shoved down our throats to make a few extra bucks. Nobody is fooled by this. The posts are right, this isn't innovation. There doing this to make more money and save costs. The problem is the saving will not be passed to the consumers. Soon you will be forced to buy plastic everything. Reply
  • Galvin - Friday, September 19, 2003 - link

    I think Asus will make ATX style boards with PCI express on it. Least this way we can upgrade to pci-express without throwing away our expensive cases.

    As far as cooling I have no problems with it at all. Lian-li all illuminum case and all copper heat sink from zalman do more than enough cooling.

    This new case design is nothing but people to spend a lot of cash. But like I said I think will be able to get pci-express ATX boards from makers like asus, so no need to jump this new BTX crap right away.
  • Anonymous User - Friday, September 19, 2003 - link

    Well I am personally not impressed.

    Not providing AGP support at all is going to delay enthusiasts from switching to the new Form Factor.

    Saturating the cool air immediately by passing it over the CPU and then passing it over the other components is a big mistake as by that point it will be significantly less affective at cooling as you cannot increase the volume of air flowing over those components to compenesate for the higher than ambient temperature you have now.

    They should be looking at putting more active cooling into the current format before putting this BTX crap out
  • Anonymous User - Friday, September 19, 2003 - link

    Are we ever going to see the PCI Express systems allow for multiple video cards? With new video cards, they allow multiple outputs for monitors. I still think it would be nice to have three screens being pushed by different video cards. I was never aware of Intel building a chipset that would support two AGP slots. Is this PCI-X16 slot strictly for video or can you stick your video card wherever you want if you have a mobo full of PCI-X slots? Reply
  • Anonymous User - Friday, September 19, 2003 - link

    Intel wanting more royalties mayhaps? Wouldn't be the first time they changed somthing with that as the primary goal. Reply
  • n0d3 - Friday, September 19, 2003 - link

    it's not so bad really,

    by flipping the case, add on cards are finally facing chips upwards again, and that is a lot better then having them downwards. it can get rid of the heat easyer. And the CPU beeing infront isn't really that new either, a lot of socket7 boards where like that.
  • Anonymous User - Friday, September 19, 2003 - link

    Change for the sake of change... or control of the motherboard, power supply, and case industries. You take your pick based on your view of Intel. None-the-less, the only thing worthwhile in the whole BTX design is the cooling. The right swapped to left is in a word "unnecessary." Just flip the pictures in this report left to right in your mind and you'll see that there was no compelling reason for the change... unless you subscribe to a darker image of Intel (as I do) that this is as much about controlling the industry as it is about innovation or change for the better. Reply
  • Anonymous User - Friday, September 19, 2003 - link

    #15, there are PS/2 keyboard and mouse to USB converters. :) I have a couple IBM Model M too, best keyboards ever! :))
    On the other hand, USB for mouse and keyboard SUCKS!!! USB has high latency, and uses lots of processor time, **total crap** for gaming control!! :((
  • McCarthy - Friday, September 19, 2003 - link

    Miss the old Articles forum...Anonymous User sure talks a lot.

    I guess I'm missing the point of BTX too. For OEMs having the 'thermal module' upfront so they can use the combine the functions of CPU heatsink's fan and case fan will reduce cost slightly, but then Dell's already been doing this quite effectively as is with their neon green duct. Removing Parallel-Serial-PS/2 is a function of the ATX backplane included with the moterboard, as made ever so obvious by including parallel and PS/2 in the BTX example case. The most innovative thing I'm seeing from the examples you were given is the notched PSU allowing for a skinnier case.

    What I don't see are demands for uniform motherboard-case plugs for Power/Reset/lights. I'm also failing to see how having the motherboard face the other way makes PCI Express or Serial ATA any easier a transition. Frankly, aside from allowing OEMs to have a nice centrally mounted grating for the input fan over their 'thermal module' rather than an offset one in the back, I don't get the point at all. Looks like a 1964 and a half Ford revision where nothing is really changed, but parts houses and mechanics get overhead because of it.
  • Serp86 - Friday, September 19, 2003 - link


    My 9 year old pentium 1 60mhz board had this config. only the case had a 120mm fan instead of the 80!!!

    Who called this "innovation"!?

    LOL. In Intel's Face.

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