AMD Phenom CPUs to support DDR 3?
AMD's Phenom processors weren't expected to gain DDR 3 support until H2 2008 when the chip maker introduces its Socket AM3 interconnect. But documents posted on the company's website show the upcoming, Socket AM2+ versions are DDR 3 compatible too.
AM2+ is all about supporting HyperTransport 3, the latest version of the technology AMD uses to connect its processors to host computers' system chips. AMD has said AM2+ will support DDR 2 memory, controlled using its CPUs' built-in memory manager hardware.
DDR 3, on the other hand, already supported by Intel's P35, G33 and other 'Bearlake' chipsets, hasn't officially been due to be supported until H2 2008.
However, AMD's BIOS and Kernel Developer's Guide for AMD Family 10h Processors, essentially the chip series' low-level programming bible, reveals "support for DDR 2/DDR 3 DIMMs in product variations".
Of course, AMD would want to architect in DDR 3 support, in order to ensure the second-generation Phenoms - and, indeed, the recently released 'Barcelona' third-generation Opteron server CPUs - are able to handle DDR 3 in the near future without AMD having to design a whole new memory controller and re-validate the chip with this new component.
The question is, will Phenoms be able to use DDR 3 out of the gate, or will their use of the Socket AM2+ bus preclude support of DDR 3 until AM3 comes out?