These are form factors (size and shape) of motherboards you can plug CPUs into. They have no speed in themselves. For example, both ATX and micro-ATX (there is no mini-ATX) boards are available for most recent CPUs, making them the same speed with the same CPU.
The differences between them are more along the lines of the size of the case it will fit in and how many expansion slots they have.
BTX hardly exists anymore, it was a form factor proposed by Intel but cancelled in 2006.
If you are in the market for buying one of them, I suggest going for one of the common standards: ATX (standard desktop tower size) or micro-ATX (a bit smaller)
The two ATX standards are for all practical purposes the same except for the size and the number of expansion slots.
See related link for more form factors.
Yes, if it is an ATX motherboard. The motherboard specifications should say specifically if it is ATX, mini ATX, BTX, ITX, etc. Most motherboards are ATX.
The three form factors for desktop system boards are: ATX, and BTX and NLX
There's actually three: ATX, Mini ATX, and Micro ATX. The difference is only in size. Mini is about half the size, Micro is 1/3 But of course with the size, you sacrifice extra ports, usually PCI expansion ports.
ATX
BTX
Three form factors are AT, ATX and BTX. AT is the older Pentium, real big with just a few connectors. ATX is the most common today, mid-size, more standard connectors for future devices, the power supply is placed differently to work better and the placement of RAM is closer to the CPU which enhances performance. BTX, is designed for powerful computers so the cooling system is improved, the CPU is moved to the front of the motherboard to get cool air and has a special heat sink and an assembly on the CPU that blows air away from the CPU.
ATX and BTX are types of motherboards designed by Intel. ATX is the more popular motherboard and has been around since the mid 90's and was designed for the ease of adding and removing components. BTX boards are newer then ATX and were designed to provide better airflow throughout the computer while maintaining the benefits of the ATX design. BTX has improved air flow , can be used in all cases and is able to use ATX power supply.
atx,nlx,btx
The main difference between ATX and BTX, is that BTX rearranges components on the ATX board to improve thermodynamics. Components changed that reduced the heat production within a PC, negating the need for the switch to the BTX board.
Atx, btx, nlx
ATX or BTX
ATX motherboards are best suited to providing legacy slots and ports (such as PCI).