ATI R600 To have External 512-bit Bus?

Fudo over at The Inquirer reports that ATI's next-generation R600 GPU is rumored to have an external 512-bit bus. Should the rumor prove true it might go a long way in explaining why the industry won't see ATI's flagship DX10 GPU until Q1 2007. Here, the use of an external 512-bit memory bus requires a significantly more complicated PCB design as more physical pins are required and appropriate traces need to be made. There is little doubt that once ATI is able to deliver R600, it will be more than enough to give NVIDIA a run for their money. However, with NVIDIA's next generation G80 rumored to be launching within the next few weeks one has to wonder if some of the design choices ATI made were worth giving NVIDIA a monopoly for the next few months.

If the 512 memory ring turns to be the real thing, we are talking about 128 GB/s of memory bandwidth with GDDR4 clocked at 2000MHz. We also learned that the R600 may use memory faster than 2000MHz as it will be available by Q1. If ATI keeps pushing the chip we might get even faster GDDR4 chips at production time.
Tags:  ATI, bus, AV, R600, external, XT, BU