Oh dear....this doesn't look good. I think Sony should be kicking themselfs right now.
For those who want the facts straight away -
"For main memory, it looks like Cell has about 25GBps of main memory bandwidth, and RSX is about 15-20GBps. Achievable bandwidth is between about two thirds of that and nearly 100%, clearly the elves in the caves surrounding Rambus central did something right with XDR. That is the happy news.
For local memory, the measured vs theoretical bandwidth is missing, I wonder why? RSX is at a solid 22.4GBps for both read and write, good job there green team. Then comes the blue team with Cell. Local memory write is about 4GBps, 40% of the next slowest bandwidth there. Then comes the bomb from hell, the Cell local memory read bandwidth is a stunning 16MBps, note that is a capital M to connote Mega vs a capital G to connote Giga. This is a three order of magnitude oopsie, and it is an oopsie, as Sony put it '(no, this isn't a typo...)'."
"The next slide goes on to say "Don't read from local memory, but write to main memory with RSX(tm) and read it from there instead", and repeats the table numbers. This is very very bad. The number of times the presentation goes on to say that it is correct, and the lack of anything like "this will be fixed by production steppings, so take measures X, Y and Z" say to me that it is not a fixable snafu. Remember at E3 when I said that the PS3 demos there were object sparse? Any guesses why?"