Quarks: Nothing.
This is just a way to switch to three, two, or one CPU if you want to for any purpose at all.
Jase: At boot time the entry /numproc sets the number of CPUs that will be enabled, until next boot when boot.ini is read again.
Now - whether or not Microsoft / Intel got it right and can actually turn off a physical CPU, or just reduce the total CPU capacity to the capacity of 1 CPU, I am not sure, I don’t have a dual-core machine. If you can display the usage for each CPU then it will be visible.
You need to remember to enable the remaining CPUs when you have finished testing.
Your affinity tip is correct, in as far as running a particular application on a certain CPU, but all CPUs will be enabled if they are not disabled as above.
Note: CPUs are disabled in reverse order, you cannot select which one. CPU 0 is never disabled…
Reminisces…
… After all, this is not one of my “ancient” and “dynosaur” mainframes that you youngsters laughed at not so long ago, that would let you do this so easily. Now you are getting those old “ancient” and “dynosaur” functions in a box less than 1 cubic foot instead of 32 cubic metres, that’s the only difference. You lot will just have to struggle a bit longer while Intel and Microsoft and Sun and others play catchup-with-the-good-old-mainframe, and believe how wonderful they are to have “invented” this stuff! Ha! They’ve only just now found “Virtual Machine” in software - IBM had VM software in the late 1970s. Ours had it in hardware timeslice in the 1980s, just to let customers get rid of IBM’s costly VM. But then again my beard is long and white now, and after all when I was young we never believed old people, too convinced they were telling us yarns… 😄
Ruminates…
Anyhow, that technology is too advanced for you right now, it would blow your minds because you’ll want it in your “cubic foot” and you can’t have it yet. But Intel might “invent” it again just for you, soon… 😄
And gives up…
And as for “Virtualisation”… aaahhh, what’s the use?..!! 🔨