The Inquirer has some information about the types of memory the R420 from ATi and NV40 from NVIDIA will support.
ATI'S TEAM headed by Dave Orton team has no intention of slowing down after its successful coup with the R300.
You will be run over if you stop for even a second in the graphics business and even R420 is still not totally cast in stone.
Someone at ATI is thinking of the next speed update of this chip that should come roughly six months after.
ATI is acting far sightedly. It will have support for all memory marchitectures in R420 as the chip will support DDR1 and that could mean cheaper cards, it will support DDR 2 that will be the memory of choice for this chip and then there's GDDR3 memory, which could be used in future speed upgrades of the R4x0 family.
We understand that the initial R420 will use DDR 2 memory which is finally stable and available, and can deliver over 1000MHz.
The R300, R350 and consequently R360 also had support for DDR 1 and DDR 2 as R350 had its DDR II version following introduction of R350, Radeon 9800 PRO 128 MB DDR 1 few months earlier.
The R420 will have 256 bit memory interface that can always be cut up to 128 bits if you need that.
Will NV40 work with GDDR3 and DDR 1. We think it should better have those capabilities.