P, when they speak of "low Yields" by the dram makers, what exactly does this
mean?
Yield means how many good ones a chip company gets when it runs a batch (actually a wafer, or wafers) of chips. It's expressed in percent, and 100% is the best you can get (of course). I can't speak for what percentage yields the DRAM makers get, but I can guess. I do know that Intel and IBM, who are pretty well accepted as the best in the world at making chips, get 70 - 80%, (I'll put in a +/-3% or so confidence factor like the political poll people do) on matured products where they've gotten all the process bugs out. Low yields could imply as low as 10 or 20% (actually can be zero), up to 30 or 40%. I would guess that they are getting as low as 10 - 20%, or worse, based on the context in which the article stated it.
DRAM companies probably get the 70 - 80%, +/-, like Intel and IBM, when things are right.
Tony |
