Maybe the same reason we didn't have built-in clocks until after there
were five dollar LCD wris****ches. I don't know.

My current clock is very accurate (MSI mainboard).

wrote:

Why do the battery powered clocks in personal computers tend to keep
worse time than quartz watches, even the $1 ones?

The computer batteries measure fine, at least 3.15V.

I thought that the problem was temperature swings in the computers
(25-38C), but a couple of cheapo watches taped inside the computers
kept better time.