While Advanced Micro Devices advices its mainboard partners who make platforms to support processors of today as well as future dual-core chips, at least some platforms made now may require BIOS update even for new revision of the Athlon 64 as a result of a change in thermal specifications of the chip, which causes questions about compatibility with forthcoming chips.

Some Mainboards Face Compatibility Issues with AMD’s Future Chips

The Inquirer web-site last week published a number of news-stories in regards compatibility of the AMD Athlon 64 revision E0 with different mainboards shipping today, particularly those based on popular NVIDIA nForce3 and 4 chipsets. NVIDIA, who said there were no compatibility issues between its chipsets and AMD’s new processors, pointed out that “a couple” of mainboard makers did not follow AMD requirements, but were still able to tackle compatibility at least on some of their mainboards issue with BIOS update.

According to The Inquirer, mainboards from ABIT and EPoX will only be able to support AMD Athlon 64 revision E0 with a special revision of the BIOS. The web-site did not report which mainboards are affected and when and if the BIOS is released.

“It seems that a couple of motherboard partners did not design their mainboards to AMD’s thermal requirements for [AMD Athlon 64 processor] revision E. A BIOS update from EPoX and ABIT would fix the issue. It has nothing to do with nForce4 and is not apparent on the majority of boards available in the market. Thus, for the rest of the manufacturers, a BIOS update is not necessary,” a spokesman for NVIDIA Corp. told X-bit labs.

AMD Athlon 64 and Athlon 64 FX processors revision E0 are those based on AMD’s cores code-named Venice and San Diego respectively. The desktop AMD64 processors with E0 revision are expected to feature SSE3 technology in addition to several performance improvements and bug fixes over those found in previous revisions of AMD Athlon 64 processors made using 90nm process technology.

AMD Opteron processors already acquired E0 revision as well as SSE3 technology.

AMD’s Athlon 64 Revision E Has Spec Changes

“AMD has changed voltage/thermal settings with [AMD Athlon 64 processor] revision E0 and that caused problems, but we could luckily change this with a BIOS update. Fortunately, [AMD Athlon 64 processor revision] E4 is not broadly available, so there were not so many complains from customer side,” an EPoX spokesperson told X-bit labs.

At press time the company’s English web-site did not provide any BIOS that supported AMD Athlon 64 processor revision E0.

Two representatives at ABIT Computer – in Taiwan and the USA – did not respond to enquiries seeking for comments. ABIT currently supplies five Socket 939 mainboards that are potentially compatible with AMD Athlon 64 processors revision E, but also currently does not provide any specific BIOS version to tackle alleged compatibility issue with the mentioned chips. At the same time the company last year released a BIOS version that brought “enhanced compatibility with D0 stepping FX-55 and 3200+ CPUs.” Back in 2001 the company’s top-end KT7A mainboard powered by VIA KT133A chipset required a new revision to support AMD Athlon XP processors.

Advanced Micro Devices also did not comment on any specification changes for its AMD Athlon 64 processor revision E processors and potential compatibility issues with mainboards from other makers.

Currently AMD advices its mainboard partners to support 80A current in CPU power supply circuitry and maximum thermal power of 105W with their platforms in order to enable future dual-core processors. The company said its dual-core AMD Opteron will also require BIOS update to function properly.