AMD declared yesterday that their 754-pin and 940-pin processors with 1000MHz HyperTransport bus, which will be launched in 2004, will be backwards compatible with current motherboards.
“HyperTransport is a flexible protocol. A current specification for it is 800MHz, yet some chipsets currently run 600MHz. That is okay, the CPU just sets itself to the frequency the chipset can handle. Likewise, a future AMD64 processor capable of 1000MHz HyperTransport, is still backwards compatible with mainboards that run their chipsets at something less than 1000MHz,” an AMD spokesperson said.
Generally, compatibility between components of different generations means a huge benefit for companies that deal with inventory, e.g. mainboard makers and PC makers.
According to the recent roadmap, next year AMD will release faster versions of its 64-bit microprocessors made at both 0.13 micron and 90nm nodes and will also broaden its 64-bit lineup with some low-cost offerings. The family of AMD64 products for desktops planned to be released next year contain chips for Socket 754 with 1MB of 512KB of L2 cache and single-channel memory controller as well as for Socket 939/940 with 1MB of cache and dual-channel memory controllers. Besides, there will be 754-pin CPUs without AMD64 instructions and marketed under AMD Athlon XP brand-name.
FSB and Socket compatibility are generally not the only terms of compatibility between a mainboard and a microprocessor. In case a mainboard cannot provide enough power or current for faster chip with higher consumption, such platform will not be able to work with the processor. For instance, Intel’s higher-end Pentium 4 “Prescott” processors will not be able to work with quite some Socket 478 mainboards that feature 800MHz Quad Pumped Bus because of unexpectedly high power consumption of Intel’s next-generation processors due to be released on the 2nd of February, 2004.