It's not true that Intel changes PC platforms as often as a snake sheds its skin: Most adult snakes shed about once a month, and Intel chipsets last weeks longer than that. Even so, by its usual standards the silicon king has been slow to provide a full platform lineup for its 45-nanometer-processs Core 2 Duo and Quad CPUs. This month's new 4 Series chipsets fix that.

The four new desktop chipsets supplement the already released Intel X48 Express, a top-performing chipset designed for the enthusiast market. The P45 Express is the mainstream performance option, while the G45 Express provides similar features but adds high-definition integrated graphics. Throw in slightly scaled-down P43 and G43 Express variants, and Intel finally has an up-to-date Core 2 chipset family.

Well, almost up to date, anyway.

The Mainstream-Plus P45

The X48 satisfied the need for an ultra-high-end home for the 45-nanometer Core 2 Duo, Quad and Extreme processors, luring overclocking enthusiasts and hardcore gamers with features like a 1600MHz front-side bus and support for speedy DDR3-1600 memory. But the X48's steep price tag and sizzling feature set make it a niche product at best. Intel's new P45 Express chipset looks to fill that mass-market gap, taking over from the popular P35.

In most ways, the P45 looks a lot like the P35 chipset it's supposed to replace. Both offer mainstream specifications such as support for the 1333MHz front-side bus, DDR3 at up to 1066MHz (17GB/sec), DDR2 at up to 800MHz (12.8GB/sec), PCI Express 2.0, and Intel's HD Audio, Matrix Storage Technology, and Turbo Memory features.

In fact, from a glance at the base specs, the P45 and P35 Express chipsets look virtually equivalent. The lack of a higher-speed DDR2 or DDR3 option is very strange, as DDR3-1066 is already old hat -- 1333MHz seems to be the entry level right now.

One upgrade has been the formal adoption of dual PCI Express 2.0 slots, for use with dual-GPU AMD CrossFire technology, but with a caveat of only 8 lanes per card rather than the full 16. This isn't really much of an improvement, as several P35 Express motherboards already featured multi-GPU support through either x8/x8 or x16/x4 lane configurations; the P45 is more of an official Intel confirmation of CrossFire support, rather than a true feature upgrade. The new chipset also officially supports all 45-nanometer Core 2 Duo and Quad processors, a capability still dependent on BIOS and vendor support where the P35 is concerned.

Even the Southbridge upgrade from the ICH9/R found on the P35 (and X48) to the ICH10/R of the P45 is no major shift, as each includes the same basic features such as a dozen USB 2.0 ports, six PCI Express x1 lanes, Intel Gigabit Ethernet, and six SATA 3.0GB/sec ports with eSATA.

To be fair, the P45 does include Intel's Extreme Tuning Utility, a program that will allow users to fine-tune their platforms for maximum performance. This could possibly bring the once-obscure concept of overclocking into the spotlight.

The G45: Looking Good

By contrast, the Intel G45 Express chipset is more of a true upgrade, with many enhancements over its G35 Express predecessor. To start, the new platform adds DDR3 memory support, following the P45 design with speeds up to DDR3-1066 and DDR2-800. The G45 is also a full-fledged PCI Express 2.0 chipset. As with the P45, nothing much has changed on the CPU side, with front-side bus speed peaking at 1333MHz and official support for all 45-nanometer-process Core 2 CPUs.

The Southbridge also represents a more prominent upgrade, as the default G35 configuration featured the older ICH8/R rather than the ICH9/R found on the P35. The updated G45, like the P45, includes the latest ICH10/R silicon. This two-steps-ahead move means that some features remain consistent, like Intel HD Audio and six PCI Express x1 lanes, while others like Intel Turbo Memory, eSATA, and additional USB 2.0 ports are new.

But the most obvious shift is the integrated graphics core, where the G45 introduces Intel's Graphics Media Accelerator X4500HD successor to the X3500 found on the G35. The new core is compatible with Microsoft DirectX 10 and Shader Model 4.0, with OpenGL support promised via a forthcoming driver update. It also offers Intel Clear Video Technology, with full hardware acceleration for MPEG2, AVC, and VC1 formats for 1080p HD video playback. Image quality is also enhanced through advanced deinterlacing and post-processing algorithms and color control options. The X4500HD even supports cutting-edge outputs such as HDMI and DisplayPort as well as VGA and DVI.

Inside the GMA X4500HD

On the surface, the GMA X4500HD looks very similar to the X3500 graphics core found in the G35 Express chipset. The latter is also compatible with DirectX 10, Shader Model 4.0, and OpenGL 2.0, and maintains the same basic architecture. The X4500HD is slightly more robust, with 10 unified shader processors with enhancements in the areas of floating-point and filtering performance, but is also clocked at a slightly lower speed.

The newer core's primary advantages come from its native PCI Express 2.0 architecture, its enhanced connectivity options, and the HD suffix in the product name. Intel is obviously concentrating on high-definition video and image quality features for the GMA X4500HD, rather than looking to upgrade 3D rendering or gaming performance in any meaningful way. This integrated graphics core will offer full support for Windows Aero, but the initial lack of OpenGL 2.0 drivers is a concern, as Intel had great difficulty fulfilling driver promises for the G35/X3500.

The P43 and G43 Tone it Down

The Intel P43 and G43 Express chipsets round out the 4 Series family and, as in previous generations, represent lower-cost, cut-down versions of their higher-numbered counterparts. The P43 is a toned-down version of the P45 without dual-GPU graphics support, making it much like a G45 without the integrated graphics. The G43 follows the same pattern -- it's functionally equivalent to the G45, but the clock speed of its built-in graphics core lower. Depending on the price, these both look like potentially good deals, especially if the missing features are not that important to you.

Still, it's hard not to view the latest Intel chipset announcement as a little underwhelming, especially after the strong start represented by the X48 Express. For the most part, the 4 Series is merely an evolutionary upgrade from the 3 Series, intended to give users a rock-solid base for the latest 45-nanometer-process Core 2 CPUs. The P45 is particularly unexciting.

The lack of bleeding-edge FSB1600 support is understandable, but the conservative DDR2-800 and DDR3-1066 memory caps are very disappointing, especially as DDR3-1333 and -1600 are soaring in popularity. Other than the addition of GMA X4500HD graphics, Intel seems to be joining NVIDIA in releasing a new family of chipsets whenever it feels the need.