What is a riser card?

A riser card, sometimes called a riser board, is a circuit board used in some computers, and occasionally other electronic devices as well, that allows other circuit boards to plug into a main board at a different angle. Typically, a riser card plugs into a motherboard or controller board perpendicularly, allowing another expansion card to plug into the riser card. The expansion card will then be parallel to the motherboard, which can save a lot of space, especially in a smaller computer. Without the riser card, the expansion card would be sticking up perpendicularly from the motherboard, taking up much more vertical space.

Unlike expansion cards, riser cards themselves typically do not add any functionality to a computer. They are used like connectors or adapters, allowing another circuit board to connect to the main board in a way that it otherwise would not be able to. Riser cards are in effect "dummy" circuit boards -- they don't really do anything, besides providing a connection from the contacts on one side of the card to the contacts on the other side. However, there are riser cards that do provide additional features, like the ability to translate from PCI to PCI Express, for example.

Riser cards come in many different types, to accommodate many different types of expansion slots. You can find ISA riser cards, PCI riser cards, AGP riser cards, and PCI Express riser cards, among others. Like the expansion slots themselves, riser cards are only compatible with expansion cards that use the same standard. A PCI riser card, for example, could connect to a PCI slot on a motherboard and to a PCI expansion card, but it would not be able to be used in an ISA motherboard slot or with an ISA expansion card.

Many riser cards only allow one expansion card to be plugged into them, much like a phone line coupler has one port on each side. However, some riser cards also act like a phone line splitter, enabling two or even three expansion cards to connect through the same expansion slot on the motherboard. These riser cards allow for increased functionality in addition to saving space inside the computer chassis.

Many examples of riser cards can be seen online. Search a site like Newegg.com for "riser card" and you can see all of the different models and styles available.

(Originally posted on Helium.com, Nov 2012. Image courtesy of blickpixel from Pixabay.)