Intel G965

The latest Intel chipset with integrated graphics is iG965 that was announced together with the Core 2 Duo processors. It formally supports all these processors, which means that any mainboards built around this core logic set should be compatible with them, too. In fact, there is nothing revolutionary about the iG965. The chipset acquired unofficial support for DDR2-800 SDRAM and a new ICH8 South Bridge that allows implementing 10 USB 2.0 ports and 6 Serial ATA ports. Moreover, ICH8 has no Parallel ATA interface support, so all the iG965 based mainboards can only have this interface implemented via additional onboard controllers.

The major innovation in iG965 is the completely new graphics core aka Graphics media Accelerator X3000 (GMA X3000). This is not an evolutionary development of the GMA 950. This core features some drastic architectural changes compared with the predecessors. First of all, we should point out the fact that GMA X3000 has finally acquired hardware pixel and vertex shaders. Intel claims that this makes GMA X3000 compatible with Shader Model 3.0 and compliant with Microsoft?s hardware requirements for Vista Aero Premium Interface. Moreover, the changes have also touched upon the video encoding capabilities. In particular, GMA X3000 got hardware WMV9 acceleration that was absent in the previous chipset models.

The architecture of GMA X3000 is built as an array of programmable units, each of which can be programmed to work as a pixel or vertex pipeline or to serve for video playback acceleration. The units get assigned the appropriate function depending on the workload falling on the core and there is a unified arbiter responsible for this management. This flexible GMA X3000 architecture allows us to believe that the core may eventually become compatible with DirectX 10 with only driver enhancement.

The GMA X3000 graphics core built into the iG965 chipset works at 667MHz frequency and features 8 programmable pipelines. To compare this core against the traditional graphics core designs Intel declares the fillrate of 1333Mpixels/s. In other words, this characteristic of the new core is lower than that of the older GMA 950. This may cause iG965 to fall behind i945G in some benchmarks, although GMA X3000 boasts higher shader processing speed.

GMA X3000 supports maximum 384MB of graphics memory (shared with the system RAM). The integrated RAMDAC works at 400MHz, and the maximum supported screen resolution is 2048x1536 at 75Hz vertical refresh rate. Of course, GMA X3000 supports DVI interface, although it will still require special daughter cards installed for proper DVI implementation.

Note that iG965 is the only chipset with the integrated GMA X3000 graphics core. Some budget chipset from the 965 series, such as iQ965 and iQ963, use a slightly different core, GMA 3000, that has no hardware shaders and no special functions for accelerated video encoding, which appears closer to GMA 950 rather than GMA X3000.

Today we are going to discuss only GMA X3000, since GMA 3000 is targeted for low-end systems.