How Time Flies
About four months have elapsed since the launch of Intel's second generation of Centrino mobile technology, known by the codename Sonoma . At the time, the lack of a corresponding test device meant we were unable to thoroughly test the new Intel 915GM, which features integrated graphics core and a PCI Express interface. Accordingly, we were unable to say whether, and to what extent, the new chipset is superior to its AGP predecessor, the 855GME.
It's therefore high time that we compared the graphics and system performance of a Centrino device of the second generation with one of the first generation. We decided to put the Dell Latitude D610 into the ring as a current Sonoma notebook with the 915GM chipset. For our representative Centrino device, we chose the Uniwill223II0, which forms the basis of our DIY notebook project.
Before we introduce the Dell Latitude D610 in more detail, we wish to briefly remind you of the technical innovations brought to notebooks with the introduction of the 915GM chipset.
915GM Vs. 855GME
The 915GM is a member of the Mobile Intel 915 Express chipset family, which may be more familiar to you under the codename Alviso.
Aside from the PCI Express bus standard, Alviso signals the notebook debut of CPUs that have a higher clocked Front Side Bus (FSB) and nominally faster, energy-saving DDR2 memory. What's more, the chipsets now offer manufacturers the option of offering SATA interfaces, Intel's High Definition Audio and the new Expresscard I/O interfaces in the notebooks as well.
Block diagram of the Mobile 915GM chipset
The graphics core of the 915GM is based on the Graphics Media Accelerator (GMA) 900, also found in the 915G and 925G desktop chipsets. Accordingly, the graphics core is DirectX 9-compatible, but not DirectX 9-compliant. The distinction is that while it has a total of four genuine pixel pipelines, the vertex shader(s) on the other hand, are emulated by the CPU. In contrast to a dedicated graphics processor offering full DirectX 9 hardware support, like ATi's MR X300 or Nvidia's GeForce Go 6200, vertex shader performance and thus 3D performance of the GMA900 depends on the strength of the CPU.