Mobile PCI Express Module

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.

A common misconception about MXM is that a certain model graphics card (e.g. Nvidia GTX 980M) "is MXM 2.1", and therefore any notebook with a GTX 980M 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

• Clevo has been utilizing fully standardized MXM cards on all of its high-end notebooks for the past few years.
• MSI uses standard MXM on almost all recent GX and GT series laptops. They provide excellent BIOS support with MXM structure and have had the largest number cases in which a laptop was upgraded beyond specification.
• Alienware has been using MXM on almost all notebooks. Since being bought out by Dell, they use MXM (3.0) on all of their notebooks excluding the m11x and the m14x
• Dell now uses MXM 3.0 on its Precision series, including the m6500, m4600 and m6600.
• HP uses MXM for most of its Elitebook business series (15–17.3") and workstation blades with a Q3000M GPU, with a K3100M due in February 2014. Modern Elitebooks are using completely standardized cards, while in the past they were proprietary. HP also used MXM on the Firebird HTPC and HDX Dragon.
• Lenovo used MXM on its discontinued 17" workstation line (w700(ds) and w701(ds), though it is not compatible with other cards due to BIOS/vBIOS and possibly electrical routing issues^[1]) and has used it on a few Ideapad series notebooks.
• Apple used MXM cards for their 20" and 24" iMac desktop computers. As with full-sized PCIe GPUs, the cards must be capable of accepting the installation of Macintosh firmware in order to work with Macintosh drivers.
• Most Acer Core 2 Duo era notebooks with discrete graphics cards support MXM. Since the i5/i7 chipset, only 1 Acer model has been released with MXM.
• Quanta has a number of MXM notebooks, but compatibility with other MXM cards is questionable.
• Shuttle has an MXM SFC, the x100, that is MXM compatible.
• Asus utilizes non standard MXM modules in most of their laptops, with a reversed pin on configuration on most MXM 2.1 models (since MXM 3.0 they are no longer reversed) and nonstandard PCB shape and mounting.
• Compal Electronics' (I)FL90 series uses replaceable MXM. Compal is also the original design manufacturer of many Acer laptops.
• Toshiba uses non standard (i.e. proprietary) MXM on many of their laptops, but have produced some standard cards.

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.

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 3.1 was released in March 2012 and added PCIe 3.0 support.^[3][4]

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. The initial 3.0 technical brief (not the actual spec) can be found here. The 3.0 Electromechanical specification can be found here

Module compatibility

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

List of MXM cards

MXM 3.x cards

*Unified Shaders : Texture Mapping Units : Render Output Units

External links

• MXM-SIG
• [ MXM Upgrade] - Site about MXM, with a table of some MXM laptops, detailed upgrade procedures and MXM cards for sale, no longer updated.
• - Nearly complete list of Acer laptops implementing MXM.