3. Napa Vs. Sonoma, Continued

In the W5 Asus notebooks, a heat pipe cools the Northbridge (not shown).

Like its predecessor, the 945GM uses a portion of system RAM as video memory. Up to 224 MB of system RAM may be dynamically allocated for image processing, depending on demand from active applications. Intel calls this "Digital Video Memory Technology" or "DVMT."

The GMA950 driver works with the operating system to broker memory requests from 3D applications to ensure that adequate memory is allocated for their use. As soon as the driver no longer needs this memory, it is freed up for re-use.

A close-up of the Northbridge components (915GM above, 945GM below).

Since the CPU and graphics subsystem share memory resources, the 945GM thus always runs more slowly compared to a stand-alone graphics chipset with its dedicated video DRAM.

In the end it is a matter of the cost benefits of integrated graphic components versus performance trade offs. Even the 945GM's use of faster DDR2 667-MHz memory modules does not help performance in this context.

However, if a notebook does include faster DDR-667 MHz RAM, it will deliver higher peak memory bandwidth, and does indeed make a positive impact on graphics performance. Additionally, the CPU's front side bus speed has a small influence on graphics performance.

All these factors should lead to a noticeable increase in 3D performance, assuming that the notebook supports all of the features that the 945GM chipset offers. How much faster the graphics subsystem actually runs, also by comparison with a value-oriented third party solution like the ATI Mobility Radeon X300, is something we discuss below.