In the 2003 edition of [[LinuxKernel]] P195, 1200 interrupts/second was the highest frequency, above 1KHz.
The CPU must process these timer interrupts. If it were easy to “nullify” these interrupts and eliminate the CPU overhead, then we would have millions of time interrupts per second but I doubt it. The overhead is probably unavoidable.
Scheduler is a kernel component. I think scheduler divides cpu time into slots. I guess the smallest quantum is limited by this frequency, among other factors.
P350 of The same book says that scheduler runs upon timer interrupts + keyboard interrupts.
Note many people get confused by software timer vs hardware timer. Hardware timer is my focus.
Many people get confused by software interrupt vs hardware interrupts. I have a separate blogpost (interrupts=hardware interrupts #by default), but basically most interrupts are hardware interrupts. Software interrupts are simulated.