I stand corrected about the 32-bit PC1066 RDRAM that's coming out now. It only gives a bandwidth of 4.2 GB/s, as it says in this
Rambus article.
However it looks like eventually there will be 32-bit RDRAM that actually doubles the bandwidth of a 16-bit module. First, look at the chart from the article here at TomsHardware:
Text
It shows, in part:
PC1066 RDRAM Dual 533MHz 2x16bit 4.2 GB/s
PC1066 RDRAM Dual 533MHz 2x32bit 8.4 GB/s
PC1200 RDRAM Dual 533MHz 2x16bit 4.8 GB/s
PC1200 RDRAM Dual 533MHz 2x32bit 9.6 GB/s
Next, from an article about Rambus's memory roadmap:
Text
"In addition to RDRAM device frequency increases, the RIMM module width will be increased from its present 16 bits to 32 and 64 bits. This extension effectively doubles and quadruples the RIMM module bandwidth. Combined with RDRAM frequency increases, Rambus has developed a PC memory roadmap that is easily scalable to 9.6 GB/s. "
I'm still trying to get a complete understanding of this stuff myself, but it sure seems like RDRAM has the capability to continue to outpace DDR, at least in terms of bandwidth, for the foreseeable future.