By: Mark Roulo (nothanks.delete@this.xxx.com), May 1, 2021 1:12 pm
Room: Moderated Discussions
Yuhong Bao (yuhongbao_386.delete@this.hotmail.com) on May 1, 2021 1:01 pm wrote:
> The fun thing is that 4K pages probably used to be too large. On a 80386, just 8 tasks would consume
> at least 64k and probably 128k just for the page tables alone. (80386 page tables were two levels)
What assumptions are you making about hard drive seek times? And the amount of DRAM to the number or processes more-or-less running at one time?
3,000 RPM seems like a reasonable guess for late-1980s hard drives, so 50 Hz.
Halving the page size would (roughly) double the number of seeks to page in (and out) the same amount of memory. Have you measured (or modeled) this tradeoff?
> The fun thing is that 4K pages probably used to be too large. On a 80386, just 8 tasks would consume
> at least 64k and probably 128k just for the page tables alone. (80386 page tables were two levels)
What assumptions are you making about hard drive seek times? And the amount of DRAM to the number or processes more-or-less running at one time?
3,000 RPM seems like a reasonable guess for late-1980s hard drives, so 50 Hz.
Halving the page size would (roughly) double the number of seeks to page in (and out) the same amount of memory. Have you measured (or modeled) this tradeoff?