General: Underclocking a P4

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      CommentAuthorClubBarf
    • CommentTimeApr 15th 2009
     

    Hey everyone.

    Got an old server upstairs, running linux. It's a P3 1Ghz machine with 768MB ram, hardware RAID and so on. Dual power supplies, UPS, the works (was at one time, a superawesome machine).

    Anyhow, the things long in the tooth, and what with it having 8 HDD's in it, it seems wasteful, from a power standpoint. I have a P4 2.8Ghz desktop PC lying around, and I was wondering if anyone's ever underclocked one? I wanna make the new server as "green" as possible.

    I'd like to run it at about 500Mhz (the server's already overpowered) at 2/3rds or less of the standard voltage. I'm not sure that's possible - so any opinions or whatever are most welcome.

    The old server is going to be awakened by the new one, and used as a place to dump backups, before being shut down again. Once a week should suffice.

    • CommentAuthoruncleNB
    • CommentTimeApr 16th 2009
     

    I'm not so sure if you can reduce the clock speed of a modern CPU so much without making the system unstable. I've never tried to under- or overclocked a CPU but I have heared that it causes major problems when you greatly reduce the clock speed of a fast CPU because the maximum time that information can be stored in the registers and caches may expire and so the system will crash. There should be a physical limit of how much you can slow the CPU down, but I have absolutely no idea where that limit ist or wether 500MHz is above or below it.

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      CommentAuthorLolly
    • CommentTimeApr 22nd 2009
     

    It shouldn't cause that much of a problem; you're more likely to run into problems reducing the voltage. Most P4 boards won't reduce the voltage very far (if at all) so that will probably be the limiting factor.

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