Comdex 2002 Wrapup - AMD, NVIDIA & Transmeta

400MHz FSB & Barton

As we reported earlier, AMD is strongly considering migrating to a 400MHz FSB for Barton. If you ask AMD for their official stance though, it is much like their stance on the 333MHz FSB - "we're evaluating it."

It turns out that Barton will ship with a 333MHz FSB initially, and that we received directly from AMD. Remember that even at the end of 2003, shipments of Athlon XP and Athlon 64 will be an even 50/50 split - so a good deal of the market will be serviced by Barton. In an attempt to keep Barton more competitive, the 400MHz FSB would be implemented but only if chipset and motherboard designs can be reliably produced to support the spec.

The biggest issue you encounter with a 400MHz FSB is maintaining signal integrity in the traces between the CPU and North Bridge. With 200MHz DDR signaling (effectively 400MHz), noise and trace length become even bigger factors thus putting the pressure on motherboard manufacturers to work even harder. The implementation side of things shouldn't be a problem however, as most motherboard manufacturers are working on 200MHz QDR signaling for Intel's upcoming Springdale and Canterwood projects. It'll take some work, and it's too soon to have it in January but 400MHz FSB is a very simple reality to produce.