Hi wily; Re DDR calculations &c. Yes, the reason that RDRAM has the higher bandwidth in the calculations from Intel is that they provided their RDRAM solution with two channels, but only put one channel on the DDR solution.
As to whether or not it is cheaper to have two RDRAM channels than 2 DDR channels, it is not so clear. Nvidia has a dual DDR channel chipset for the P4, with integrated graphics of some sort. Costs are hard to calculate, but the cost to add an extra DDR channel is currently way, way, way below the cost of using RDRAM memory chips instead of DDR. In other words, don't look at just the cost of the northbridge chip, instead, look at total system cost.
Anyway, there are supposed to be a couple other dual DDR designs out there. For a 266MHz system, that would be 4.2GB/sec total bandwidth.
By the way, you really can't expect Intel to fairly compare technologies that they are unable to deliver (due to management errors from 5 years ago) to technologies that they are selling now. Suffice it to say that Intel is not trying to sell RDRAM to design engineers right now.
-- Carl |
