Riser card

A riser card is a special expansion card that is used as a kind of " elbow " in order to adapt expansion cards, which usually perpendicular to the motherboard (English mainboard ) are arranged in their spatial position. Frequently riser cards are 90 -degree " elbows " that causes the expansion card is no longer arranged perpendicular but parallel to the motherboard ( there are also flexible riser cards). The main application is the 19 "technology, in which, in a 1U housing a card or in 2U housing three cards are installed horizontally in this way.

In Apple Mac Pro workstations until 2010, two riser cards were used for the connection of up to 64 GB of memory. Because Apple at this time no 8GB Fully Buffered RAM bar sales, the Mac Pro Compatible officially only 32 GB.

Variants

Riser cards are available for PCIe, PCI, AGP and ISA expansion slots.

A distinction is made between passive and active cards, the latter exist only for PCI or PCIe. The passive versions of the grind and the port (s) via interconnects through easy to use only come a few small resistors and capacitors to ensure a clean signal. Active variants allow to run multiple cards on a riser card in a slot. Here is a small control electronics on the board, which is responsible for the resource management of the inserted card. More expensive active riser cards have their own bridge and thus constitute any card inserted an own bus slot. You can expand to other bus systems the bus of the host system ie. Thus, it is eg possible to extend a PCI slot for an ISA bus via riser card. Such riser cards can provide several different bus systems simultaneously.

Other riser technologies are Audio Modem Riser ( AMR), Communication and Networking Riser ( CNR ) and Advanced Communications Riser ( ACR).