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Time changeover generates Snow Leopard problems

updated 03:30 pm EST, Mon November 2, 2009

Switch from DST hurts CPU performance

The flip from daylight savings to standard time has created unusual problems for Snow Leopard owners, Apple's support forums indicate. Some Mac users note that nearing the point of the official changeover, 2AM on November 1st, their CPU usage peaked as high as 100 percent for no apparent reason. Aside from rendering software unusable, such spikes also run the risk of overheating a computer.

The bug is generally said to have resolved itself after the new time was reached. If the problem has not already ended, it can be fixed by temporarily disabling the Menu Bar clock through System Preferences. It is not known whether or not the issue is being corrected for Mac OS X 10.6.2, which should debut through Software Update later this month.

by MacNN Staff



  1. Makosuke

    Joined: Dec 1969



    So THAT'S what was going on the night before last. I noticed that one of the cores on my older MBP had maxed out, and the windowserver process was chewing up almost 100% of a CPU for no apparent reason.

    I'd assumed it was some odd glitch caused by a program I was running, but it went away before I'd gotten around to restarting.

    Didn't even think that it might have something to do with daylight savings time until reading this.

  1. GreenMnM

    Joined: Dec 1969


    Time Zone Change?

    Did anyone else's selected time zone change? I've been using the Pacific time zone since I got my MacBook (except when traveling, of course) and some time between midnight and noon my time zone changed to "Arizona" time which does not recognize Daylight Savings. (And I my MacBook has never been to Arizona, so it's not my fault.) So, my time did not appear to change.

  1. dliup

    Joined: Dec 1969


    sensational title fail

    With millions of users, it doesn't seem to be wide spread problem.

    Title should be "Time changeover causes problem for some Snow Leopard users"

  1. vasic

    Joined: Dec 1969


    Surely not here

    I have three Macs; I was awake and surfing on one of them, and nothing happened. Everything was as it should be.

  1. JuanGuapo

    Joined: Dec 1969


    oh god...

    It was probably the cron scripts that run every night.... between 1AM-3AM.

  1. DiabloConQueso

    Joined: Dec 1969


    Overheating? Really?

    [i]...such spikes also run the risk of overheating a computer.[/i]

    Really? I've kept my computer cores pegged at 100% for hours at a time (movie conversions) without risk of overheating. Sure, it gets hot, but it's supposed to, and the fans keep it within acceptable limits.

    If one or more cores were to approach overheating range, they would automatically shut down and the computer would turn off to *prevent* overheating.

    I don't think this bug runs the risk of overheating anything, nor does keeping your cores pegged at 100%.

  1. bloggerblog

    Joined: Dec 1969


    Oh That's It

    I'm Switching! :D

  1. syzygi

    Joined: Dec 1969


    It's CRON Scripts!

    You FOOL! ...It's not a bug, it not a problem. Macs are built on UNIX and they run cron to keep the system optimized. There a are 3 kinds: Daily, Weekly, and Monthly. At the beginning of the month the system runs all 3 late at night when most people are sleeping. What a bunch of troll FUD. Windows would be so lucky to only have this kind of problems.

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