Size specification / form factor of additional cards

This article describes different dimensions of additional cards and the associated common form factors that lie behind the measures. Plug-in cards can be network cards, graphic cards or other add-on cards that expand a system with additional functions.

Nvidia K20 example

Dimension of the card in the Nvidia K20 Tesla picture

• Height: 4.33" (110mm)
• Length: 10.433" (265mm)
• Slot-occupancy: Dual Slot

Length specification

• Full length (Full Length - FL): 12.28" (311mm)
• Half length (Half Length - HL): 6.6" (167mm)

Height dimensions

• Full length (Full Height - FH): 4.376" (111mm) (also described as „Full Profile“)
• Half length (Low Profile - LP): 2.536" (64mm)

Depth specification

The depth of the card is stated in the occupancy of the slot-plate of the case. This means that, for example, a single slot card may only be as wide as necessary to ensure that nearby connectors on the motherboard (i.e., PCIe/PCI/etc.) remain accessible, unless explicitly stated otherwise (e.g., Asus graphics cards):

• Single Slot (is usually omitted, as this is common): The card needs a free case slot
• Dual Slot: The card requires two free case slots
• Triple slot: The card requires three free case slots

Slot-plate height

This often leads to confusion, as the height of the slot-plate is not always the height of the card. Only with low-profile slot brackets can the card be higher than the slot bracket itself.

• Common dimensions:

Full-height: 4.725" (120mm)

Low-profile: 3.118" (79,2mm)

There is also the MD2 Low Profile standard that defines the following values:

Half-Length and Low-Profile

Proprietary standards

In addition to the usual standards, there are also proprietary sizes of cards that are, however, inevitably adhere to a standard for the size of the slot plates. The following Supermicro card is an example for this: AOC-SGP-i4 - 4-port Ethernet controller

size specification:

• card: 9,91cm (3.90") x 6,35cm (2.50"") (Length x Height)
• Slot plate sizes: standard – 12cm (4.725"), low-profile – 7,94cm (3.13")

Example of specifications

• Intel i210: length 2.64“ x 0.709“
• Intel i350 T2 Copper: length 135 mm / height 68,9 mm
• Qlogic QLE2562: Full height (6.6“ x 4.376“) Low Profile (6.6“x 2.54“)
• LSI 9261-8i: MD2 Low Profile (6.6“ x 2.536“)
• LSI 9280-16i4e: Half-Length, Full Height (6.6“ x 4.376“)

More information

• Steckkarte (de.wikipedia.org)
• Low Profile (de.wikipedia.org)

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Author: Florian Hettenbach

Translator: Alina Ranzinger Alina has been working at Thomas-Krenn.AG since 2024. After her training as multilingual business assistant, she got her job as assistant of the Product Management and is responsible for the translation of texts and for the organisation of the department.