One of the ways AMD is able to test and qualify ATI Mobility Radeon GPUs, without having to design and build numerous mobile
reference cards that fit in multiple notebook form factors, is to
produce fully-loaded, custom reference cards that'll fit into standard
PCI Express x16 slots. The cards won't be used in any actual retail
product, but they allow AMD to test all of the various features and
functionality, and experiment with clock speeds and voltages to fine
tune and balance performance, thermal output, and power consumption. @ HotHardware.com
