Mobile PCI Express Module

MXM redirects here. For MPEG eXtensible Middleware, see MPEG.

A Mobile PCI Express Module (MXM) is an interconnect standard for GPUs (MXM Graphics Modules) in laptops using PCI Express created by MXM-SIG. The goal was to create a non-proprietary, industry standard socket, so one could easily upgrade the graphics processor in a laptop, without having to buy a whole new system or relying on proprietary vendor upgrades.

Clevo/Sager and Alienware (Dell) currently manufacture and implement the largest amount of MXM cards in their laptops and are the only known manufacturers of most standard high end MXM 3.0 models for gaming. They are also the only 2 brands which continue to produce laptops with dual MXM slots for SLI or crossfire setup. MSI currently manufactures the only notebooks with the Nvidia GTX 570m in standard MXM 3.0 type B. Arima, ODM in the past for Alienware and other 'boutique' sellers have used cards that are MXM-compliant but which possess slight mechanical differences, similar to Asus MXM cards.

A common misconception about MXM is that a certain model graphics card (e.g. Nvidia 9800M GT) "is MXM 2.1", and therefore any notebook with a 9800M GT fully implements MXM 2.1. However, this is incorrect. While Nvidia defines a lot of MXM specifications, they do not manufacture or design MXM cards themselves, which mostly consist of a PCB with vRAM and an Nvidia or AMD GPU core. Therefore any model of GPU can be manufactured in MXM, but a laptop released with any particular graphics card model may or may not implement MXM regardless. This is because it is the decision of the ODM whether or not to implement MXM, not Nvidia's or AMD's.

Implementations

1st generation configurations

Smaller graphics modules can be inserted into larger slots, but type I and II heatsinks will not fit type III and above or vice versa. The Alienware m5700 platform uses a heatsink that will fit Type I, II, & III cards without modification.

MXM Type Width Length Pins Module Compatibility Thermal Compatibility Max. Power Max. GPU size [1]
MXM-I 70mm 68mm 230 I I 18W 35 mm²
MXM-II 73mm 78mm 230 I, II II 35W 35 mm²
MXM-III (HE) 82mm 100mm 230(232) I, II, III, HE II, III, HE 75W 40 mm²
MXM-IV (Deprecated) 82mm 117mm 230 I, II, III, IV I, II, III, IV

2nd generation configurations (MXM 3)

Smaller graphics modules can be inserted into larger slots. Heatsink mounting remains the same for type A and B modules.

MXM Type Width Length Module Compatibility Thermal Compatibility Max. Power GPU memory bus
MXM-A 82mm 70mm A A 55W 64-bit or 128-bit
MXM-B 82mm 105mm A, B A, B 100W 256-bit

Standard availability

MXM is no longer supplied freely by Nvidia but it is controlled by the MXM-SIG controlled by Nvidia. Only corporate clients are granted access to the standard. The MXM 2.1 specification is widely available, and the initial 3.0 spec can be found here.

Module compatibility

First generation modules are not compatible with second generation modules and vice versa.

External links

  1. Klaus Hinum (2012-05-26). "Notebook Video Card Upgrade / Replacement". Notebook Check.