Re:Ask HN: Why did stack-based CPUs lose out?
by ilyt on Sunday January 01, 2023 @11:04AM
(#34207401)
> With modern CPU's having so many cores and threads being so cheap, couldn't NASA use these for redundancy?
Think shuttle had 3 separate computers running same code and having mechanism to vote out the one giving bad output ?
There are also some automotive ARMs that are basically 2 cores shifted physically 90 degrees running lockstep and some logic to reset if they disagree
> My second question, how much more resilient are older processes with larger feature size compared to modern 6/7nm ? Compare modern with older (14nm/22nm finfet, 28nm/32 soi) and ancient (65nm or larger).
I'd imagine by a lot. Think of the charged particle basically a pulse of charge. The bigger transistors are the bigger capacitance are and the more charge you need to flip anything. Any potential damage it could cause to the chip would also increase. I didn't found anyone trying to make "same" chip in significantly different process.
Think shuttle had 3 separate computers running same code and having mechanism to vote out the one giving bad output ?
There are also some automotive ARMs that are basically 2 cores shifted physically 90 degrees running lockstep and some logic to reset if they disagree
> My second question, how much more resilient are older processes with larger feature size compared to modern 6/7nm ? Compare modern with older (14nm/22nm finfet, 28nm/32 soi) and ancient (65nm or larger).
I'd imagine by a lot. Think of the charged particle basically a pulse of charge. The bigger transistors are the bigger capacitance are and the more charge you need to flip anything. Any potential damage it could cause to the chip would also increase. I didn't found anyone trying to make "same" chip in significantly different process.