RISER CARD




A riser card is a printed circuit board that picks up a multitude of signal lines (often bused) via a single connector (usually an edge connector) on a mainboard and distributes them via dedicated connectors on the card.

There are two basic kinds of adapter cards. There is the active card. This has bus driving circuitry. There is the passive. This has no bus driving circuitry.

Riser cards are often used to allow adding expansion cards to a system enclosed in a low-profile case where the height of the case doesn’t allow for a perpendicular placement of the full-height expansion card.

A riser card is a board that plugs in to the system board and provides additional slots for adapter cards. Because it rises above the system board, it enables you to connect additional adapters to the system in an orientation that is parallel to the system board and save space within the system case.

A riser card is a right angle expansion card that is used to extend a slot for card in computer to make room to plug it in. They are most commonly used in low-profile, 1U and 2U rackmount chassis or embedded systems. Riser cards cards plug into their respective bus (they are available for PCI, PCI-X, AGP, AGP Pro, PCI Express, ISA, or other busses) and rotate the peripheral cards, that are plugged into the riser card, so that they are parallel with the motherboard. Riser cards are available in 1-slot passive risers all the way up to 3-slot passive riser cards for 2U rackmounts. For users that only have one PCI slot available on their motherboard but require more, active riser cards are available with PCI bridge chips on them to expand the PCI bus.

Bus extenders are also riser cards however they do not always rotate a card so it is parallel with the motherboard. They are used like extension cords for power outlets. They basically extend the bus to another location so it is more convenient for the user.

Different types of riser cards/bus extenders

Straight-thru bus extenders are used to increase the height of your expansion slot as well as product development and debugging. They are also widely used by production testing of motherboards and I/O boards. Some are utilized as wearout units for the connector or gold fingers in test fixtures.
64-bit-straight-extender

Straight Bus Extender

Right Angle Extenders/Risers are most popular in 1U and 2U rackmount chassis systems or low profile embedded applications that require full height peripheral cards.
32-bit right angle riser card

32-bit right angle riser card

Flexible bus extenders can be used to relocate bus expansion slots to another location. Flexible extenders in custom enclosures that have non-standard mounting locations where a standard riser would not work.
64-bit flexible extender

64-bit flexible extender

Multiple slot Right Angle Extenders/Risers are most popular in 2U rackmount chassis systems and low profile embedded applications that require full height peripheral cards. They are available with 2 or 3 slots, with bus support for PCI, PCI-X, AGP (Pro), PCI Express, and ISA expansion. For customers with only 1 PCI expansion slot available on their motherboard, active riser cards are available to expand this one slot to three slots.
3-slot PCI-X riser card

3-slot PCI-X riser card

Bus Isolation Extenders are innovative tools for developing and testing of PC add-on boards. They allow the board under test to be added and removed from the system bus, without having to power down the entire system. They offer tremendous A-Side Right Placements time and labor savings during product development and production testing.

Riser Card Directional Orientation only applies to single and multi-slot right angle riser cards. The orientation of a right angle riser card determines what direction the peripheral card will face, whether is be towards the cpu or away from the cpu in some cases. For customers using right angle riser cards, they can either choose from A-Side Right Placement risers or B-Side Left Placement riser cards. A-Side Right Placement is where the peripheral card plugs into the riser card and is facing the right side (viewed from the front of the motherboard) with the solder side down.

PCI, AGP, and AGP Pro cards and expansion slots have different voltages that affect mechanical compatibility with one another. However PCI cards that are universally keyed are compatible in both 5V and 3.3V slots. AGP and AGP Pro universal cards can plug into any 1.5V and 3.3V AGP and AGP Pro slots. 32-bit PCI Slots and Cards come in 3.3V and 5V options.

64-bit PCI Slots and Cards come in 3.3V and 5V options.

AGP Slots and Cards come in 3.3V and 1.5V options.

AGP Pro Slots and Cards come in 3.3V and 1.5V options.

For 1U systems a very low profile single-slot riser card is required with a maximum overall height of .90″ (in most cases, this
depends on the motherboard and chassis you are using), such as the PCITX4-5, PCITX4-6, PCITX8-5 and the PCITX8-6 32-bit and 64-bit PCI

For 2U systems a low profile single or multi-slot riser card is required with a maximum overall height of 2.75″ (in most cases, this
depends on the motherboard and chassis you are using).

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