Riser card
A Riser Card is a printed circuit board that gives a computer motherboard the option for additional expansion cards to be added to the computer.

Usage

Riser Cards are add-in cards that are inserted into a motherboard via an edge connector. They are oriented in a perpendicular fashion to allow for better use of limited space. This allows for expansions cards to be installed in a space where there would not be use for them traditionally.

Riser Cards are passive devices that do not require any additional power. Power is provided by the original connector and passed through the card using the edge connector on each end. Data signals are also sent through the same method to and from any connected devices and host devices.

Specifications
The main specification used in an edge connector for data transfer is the PCI Express standard. Which allows for maximum data transfer speeds of 32 GB/s when using PCIe 4.0, along with 75W of power to be delivered from the host device. Other specifications used for these cards include ExpressCard and PCI-X.

Applications

Riser Cards have applications in both industrial and consumer spaces.

Industrial
In servers, height for expansion cards limited by rack units. This is the size limits that Riser Cards must follow when being designed. A unit(U) is the traditional definition or standard for server height and how servers are made. One server unit is equal to 1.75", while 2U servers are equal to a height of 3.5". Traditionally, a 1U Riser Card can fit 1 PCI slot. While a 2U card can fit 2 or 3 PCI slots. This all depends on the size of the expansion card as some are thicker than 1 PCI slot and will cover up any additional slots.

Consumer
In small-form-factor (SFF) computers built by computer enthusiasts, PCI-E Riser Cards are used in a similar sense to a server application. They are used to sandwich a graphics card closer to a computer motherboard and are made to the same heights as server units for most applications. These have been phased out for the more flexible PCI Riser Cable and are rarely used in a modern market.

Riser Cables
Riser Cables in a computer based application allow for further distances of data transmission than traditional riser cards. These cables used a Riser Card PCB and an edge connector on each side of the cable, with a copper alloy surrounded by a plastic insulator.  This surrounds the copper to allow for the further data transmission distances.

These cables are traditionally used in modern household gaming PC's to allow for different positioning of PCI Express Cards and GPU cards in a Computer case. This allows for customization and the addition of additional parts to suit the creator or builders needs. They can additionally be installed into vertical brackets to function similarly to a Riser Card, but with further flexibility. They are also used in small-form-factor PC's to allow for a GPU to be positioned behind a computer motherboard.

See also
 Daughterboard

References

External links
 Riser Card Installation

Computer buses
Motherboard
Printed circuit board manufacturing