A Mobile PCI Express Module is an interconnect standard for GPUs 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.
Implementations
Clevo has been utilizing fully standardized MXM cards on most of its high-end notebooks for over a decade.
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 on all of their notebooks excluding the M11x and the M14x.
Dell has used MXM on its Precision series starting from the M6600 and M4600. Before that, starting all the way from the Precision M40 in 2001 the modules were Dell proprietary. Starting from the Precision xx30 series the MXM slot was dropped again in favor for the proprietary Dell Graphics Form Factor slot.
HP uses MXM for most of its Elitebook Workstation notebooks 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 uses MXM 3.0 based Nvidia Quadro cards on its current ThinkPad P71 17" workstation notebook. They also used MXM on the ThinkPad P70, their discontinued 17" workstation line and W701), and some IdeaPad series notebooks. None of their implementations are compatible with other cards due to BIOS/vBIOS and possible electrical routing issues).
Apple used MXM cards for their 20" and 24" iMacdesktop computers, later in 21.5" and 27" Unibody iMac from Late 2009 to Mid 2011, ending with the introduction of slim iMac from Late 2012. As with full-sized PCIe GPUs, the cards must be capable of accepting the installation of Macintosh firmware in order to show EFI boot screen and various function before macOS loads.
Most AcerCore 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 and nonstandard PCB shape and mounting.
Compal Electronics' FL90 series uses replaceable MXM. Compal is also the original design manufacturer of many Acer laptops.
Toshiba uses non standard MXM on many of their laptops, but have produced some standard cards.
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
MXM-I
70mm
68mm
230
I
I
18W
35×35 mm
MXM-II
73mm
78mm
230
I, II
II
35W
35×35 mm
MXM-III
82mm
100mm
230
I, II, III
I, II, III
75W
40×40 mm
MXM-IV
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 3.1 was released in March 2012 and added PCIe 3.0 support.
Module compatibility
First generation modules are not compatible with second generation modules and vice versa. First generation modules are fully backwards compatible.
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 can be found . The 3.0 Electromechanical specification can be found
Compliance
A common misconception about MXM is that certain models of graphics cards "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.
