All motherboard slots are 22mm in width, even the ones attached to 30mm-wide cards. All current keys can give cards access to two PCI Express lanes, but otherwise interface compatibility is all over the place—so far, it's been pretty easy to guess what kind of peripheral you're dealing with based on the key it uses.
The introduction of microcomputer systems with internal expansion slots made the first software-controllable modems common. Slot connections gave the computer complete access to the modem's memory or input/output (I/O) channels, which allowed software to send commands to the modem, not just data.
What kind of expansion slot should you use for your video card? There's lots of slots. To add a video card to your computer, you have to pick an expansion slot.There have been many kinds of expansion slots over the years so most motherboards contain more than one kind of slot.
AGP Motherboard Video Card Slots AGP video card slots are pretty much outdated, though still better than PCI for speed. These cards use multipliers going up to 8X in order to enhance performance, but that depends on the type of motherboard you have and whether or not it is supported.