Rambus may appear to be like a patent troll, but I think the reality is unclear.
If you've actually followed the whole history...Rambus isn't innocent, but neither is anyone in JEDEC, especially DRAM vendors.
Rambus has made some huge contributions in terms of moving forward high speed interfaces. If you look at the real story, the DRAM vendors were trying to screw Rambus out of any money for their contributions and original work, while Rambus was trying to screw the DRAM guys for using some things which rambus had pioneered and patented. Nobody is innocent.
Like it or not, unlike most patent trolls, Rambus actually does make IP that other people use. They design memory subsystems (e.g. PS3), they have designed DDR2 and DDR3 memory controllers as well (at the behest of 3rd parties that had difficulty getting high performance memory controllers).
Anyway, if you look at what Rambus is doing (
http://www.realworldtech.com/page.cfm?ArticleID=RWT120307033606&p=2), it's pretty interesting.
They are moving away from a parallel command bus towards something that looks like CSI - where command/addressing and data are all treated similarly and running at the same frequency.
Intel's aged front-side bus runs the data bus substantially faster than the command bus. The biggest the difference between the two, the lower the efficiency. GDDR1-5 works the same way.
I suspect GDDR6 or 7 will have to move to a differential, point to point command link in the future.
DK
