Another critical issue faced by notebook manufacturers and
system builders is the difficulty in simultaneously supporting multiple
platforms. Multiple platforms create increased complexity for inventory
management, logistics, and technical support. To address multiple market
segments and price points, ideally a manufacturer could simply
configure-to-order a single base platform with a range of graphics options.
Designing a system with an MXM interface provides that flexibility.
Some shipping systems are capable of supporting multiple GPUs
from different graphics vendors using the same interface. In many cases, this
allows an OEM or system builder to ship a graphics solution from one vendor at
launch, and follow up with a different graphics solution with different graphics
memory devices six months later. Ultimately, the end user benefits by having
more options, and newer graphics hardware, to choose from. According to the
notebook designers, in order to make ATi GPUs compatible on MXM, additional
power rails are required.
The primary objectives for the MXM interface are to accelerate
time to market for the latest notebook graphics, introduce additional
configure-to-order options, and create flexibility in selecting graphics
solutions. However, an additional benefit of creating a consistent notebook
graphics interface is that it provides a design specification for upgradeable
graphics in a notebook. To allow upgradeable notebook graphics, the MXM
interface needs to address two critical issues—mechanical compatibility and
Compatibility with Integrated Graphics
The signal definitions for the MXM connector were explicitly designed to
accommodate systems with integrated graphics, without requiring the display
circuitry on the motherboard to be changed. As with desktop systems with
integrated graphics, plugging an MXM board into a system with integrated
graphics immediately disables the onboard integrated graphics and instead routes
the signals from the MXM board to the motherboard display connectors. The
advantage is that this minimizes the cost of upgrading to discrete graphics,
because the connectors are shared on the motherboard with the base integrated
graphics configuration. It also allows manufacturers and retailers a simple
configure to-order graphics upgrade option.