DIYbanter - View Single Post - Why aren't computer clocks as accurate as cheap quartz watches?

wrote:

If there was an answer in this thread, I must have missed it. So many
ideas, so few applications of the facts :-)

There are two clocks in a PC (I don't know MACs) A hardware one, and the
software clock. When the PC boots, the BIOS reads the hardware clock, and
the OS asks the BIOS what time it is. From there on, good old windows or
whatever is doing the clock counting, using an interrupt timer. Given the
sloppy programming,

and the inability of windows to pre-emptively
multitask,

Incorrect.

snip