while the back-of-the-napkin math is surprisingly not terrible, of course it's a log scale so Mar's Law is relevant: "Everything is linear if plotted log-log wi

while the back-of-the-napkin math is surprisingly not terrible, of course it's a log scale so Mar's Law is relevant: "Everything is linear if plotted log-log with a fat magic marker". Mashey was really talking about workstations, not PCs. of course, the line is blurred or non-existent now. what if we look at x86ish PCs? presume that in 1995, a nicely appointed high-end PC was a 486DX-33 (w/487) and 16MB of ram. that requires 24 bits of physical address. using 3/2*bits per year estimate, we find that we need more than 32 bits around 1995+(3/2*(32-24)) = 2007. AMD64 came out in 2003/4. but my own recollection is it wasn't really the sunset for 32 bit PCs until just about that timeframe (2007 ish). so that's not too far off. now apply forward to when we "use up" 48 bits (or 52). and it would be around 2031-2037. possible? now the other thing, is that (imho) a nicely appointed PC today in 2024 is 64GB (36 bits) vs. 16GB (24 bits) in 1995. does this track? not really. the 2 bits every 3 years would predict that we'd want 64GB machines in 2011? that's not really realistic. and it'd predict that we'd want ~16TB PCs by 2025. it seems apparent that the exponential growth that was happening in the 1980s and 1990s has either slowed substantially or is no longer exponential for perhaps the last 20ish years. i think the lesson (and for Moore's law too) is that apparent exponential growth is not going to continue forever.