5 ms·
The slides are misleading. "Memory Wall" refers to the fact that CPU speed has been doubling every 24 months from 1960s till early 2000s (annual improvement rat
by bamakhrama 13y ago
The slides are misleading. "Memory Wall" refers to the fact that CPU speed has been doubling every 24 months from 1960s till early 2000s (annual improvement rate is 50%), while RAM memory speed doubles every 10 years (annual improvement rate is 10%). This "memory wall" is there regardless of the processor architecture that you use.
- wlesieutre 13y agoMath nitpick: It's a bit more complicated than that with exponential growth. You can't divide up 100% over 10 years and say it was 10% each year, instead you have to solve 2=1.1^x, and find that it doubles in 7.27 years. If something grows 10% a year for 10 years, it actually ends up at 2.59x its original size.
- greglindahl 13y agoRule of 72: doubles in 10 years, annual %age is 72/10 = 7.2%. Close to the right answer, easy to do in your head. http://en.wikipedia.org/wiki/Rule_of_72 http://en.wikipedia.org/wiki/Rule_of_72
- wlesieutre 13y agoHuh, that's a handy approximation. I'd never heard of it before.