On Sun, Aug 01, 2004 at 10:20:38AM -0500, J.A. Terranson wrote:
On Sat, 31 Jul 2004, Major Variola (ret) wrote:
Tyler D asked about how the NSA could be so far ahead. Besides their ability to make 2" sq. chips at 10% yield (not something a commercial entity could get away with)
What, exactly, would be the point of doing this?
More gates == more processing.
they can also *thin and glue* those chips into say stacks of 5 thinned die.
As easily as you could do this to high efficiency chips.
It's possible, using technologies like flip-chip. But its not as good as having everything on one die. The interconnects are limited in number and large in size, so they take up a lot of room. Stacked die are also more difficult to keep cool.
2" sq = 4 x performance
How do you figure 4x performance on a 2" chip? Most of the chip performance is tied to the total distance that signals must traverse across the chip surface.
4x the gates (roughly) means 4x performance. Chip performance, especially for highly parellizable things like key cracking, is determined by the number of gates. Eric