A few days ago some US sources reported that according to the mainboard makers, the new 0.065 micron Presler and CedarMill processors will only be supported by the i945/i955/i975 based products. The situation with dual-core Presler processors was pretty clear, as they require chipsets that support Pentium D processors. Formally, only i945P, i945G, i955X, i975X and their modifications meet this requirement in the Intel chipset product range.

Many users who have mainboards based on the older chipset models hoped that they would be at least compatible with the single-core CedarMill CPUs. Our colleagues from Anandtech didn't sound very promising in this respect. Therefore, we decided to undertake our own private investigation on the matter, especially since most mainboard makers are working very hard on getting ready for the upcoming 0.065 micron CPUs announcement. You can already come across lists of mainboards that will be actually or virtually qualified as ?Cedar Mill Ready?

Having talked to a few folks out there, we found proof that most mainboards based on i915x chipset series will be able to support Cedar Mill after the corresponding BIOS update. Even the budget solutions based on i915PL will get this opportunity. However, it doesn't mean that absolutely all i915x based mainboards will work just fine with the new Cedar Mill processors. Some of them guarantee Cedar Mill support only for the newest PCB revisions.

The most interesting thing, however, is that even i865x and i848P based mainboards will be able to work with Cedar Mill CPUs. Although here the revision number will matter even more, as the older mainboard modifications will not qualify for that.

Third-party chipsets, such as SiS 661FX/GX or VIA P4M800 also will support CedarMill CPUs after the corresponding BIOS update. Looks like the mainboards manufactured after February 2005 have much bigger chances to acquire Cedar Mill support, as this is the time when Pentium 4 6xx processors on the 0.09 micron Prescott core and featuring 2MB L2 cache appeared. They are the closest relatives of the upcoming CedarMill processors, as they have simply moved to the finer 0.065 micron manufacturing technology without any additional architectural changes. Until recently most our concerns were connected with the fact that Cedar Mill is none other but half of Presler core, and this relation to the dual-core CPU could potentially impose certain limitations onto its compatibility with the existing mainboards.

However, there are a lot of mainboards dating back to mid 2004 that will also support Cedar Mill CPUs. These are the solutions produced right after the LGA 775 platform and i915x/i925x chipsets were announced.

Anyway, if you want your mainboard to support the new Cedar Mill CPUs, you will need to update its BIOS, so keep it in mind before shopping for a new processor.

Also, I have to stress that NVIDIA nForce 4 SLI Intel Edition chipset known for its eternal conflict with the youngest Pentium D 8xx CPU models will be fully compatible with single-core Cedar Mill CPUs: all you will need is just a BIOS update.

All contemporary ATI chipsets for Intel platform are compatible with dual-core CPUs, so there shouldn't be any compatibility issues when Cedar Mill comes out.

As for the Presler compatibility with contemporary mainboards, we are going to devote a separate story to this matter later on, so stay tuned!