The difference between the GMA X4500m and the GMA X4500mHD is that the GMA X4500mHD is capable of "full 1080p high-definition video playback, including Blu-ray disc movies", the GMA X4500 does not have that capability.
The Intel Graphics Media Accelerator 4500MHD (sometimes also called GMA X4500 HD or other combinations) is a DirectX 10 capable onboard graphics adapter in the GM45, GE45 and GS45 chipset of the Centrino 2 platform (Montevina). The chip has no dedicated graphics memory, but takes dynamically an amount from the main memory (up to 384 MB).
Compared to the predecessor GMA 4500, the GMA 4500MHD has two more shaders and a 33 MHz higher core clock speed. Therefore, the chip is noticable faster than the older one (especially in 3DMark06). Still, the performance is just on par with the entry level dedicated graphics cards and therefore not suited for demanding games. Some older games like Fear can be played in low details and low resolutions |