24 Oct
2025
24 Oct
'25
12:43 p.m.
On 2025-10-24 7:33 a.m., Paul Koning via cctalk wrote:
I really wonder how much swapping of memory with disc is done internally
or how many buffers it has for files?
Time sharing was created for use
with 110 baud TTY's, so the first bench mark needs to be at that speed.
Ben.
On Oct 24, 2025, at 8:00 AM, cz via cctalk
<cctalk(a)classiccmp.org> wrote:
OS level caching of disk devices is a gennable option in M+ with split I/D.
It's actually pretty impressive; the system can do read-aheads, and also writes can
be deferred (which makes turning off the system hot very bad). I think it can also cache
the directory entry table and even a small cache of 256kb or so makes a nice performance
difference.
It's also a standard feature in RSTS/E, which can allocate up to 496 kW to the
storage cache (plus additional memory, if you want, for a ramdisk). I haven't tried
to see what the performance numbers look like with and without, that would be an
interesting experiment.
paul