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    SubjectRe: rdtsc to mili secs?
    Pavel Machek wrote:
    > >
    > > Intel PIIX-based systems will do duty-cycle throttling, for example.
    >
    > Don't think so. My toshiba is PIIX-based, AFAIC:
    >

    Interesting. Some will, definitely. Didn't know that wasn't universal.

    Clearly, on a machine like that, there is no hope for RDTSC, at least
    unless the CPU (and OS!) gets notification that the TSC needs to be
    recalibrated whenever it switches.

    > root@bug:~# cat /proc/pci
    > Bus 0, device 5, function 0:
    > Bridge: Intel Corporation 82371AB PIIX4 ISA (rev 2).
    > Bus 0, device 5, function 1:
    > IDE interface: Intel Corporation 82371AB PIIX4 IDE (rev 1).
    > Master Capable. Latency=64.
    > I/O at 0x1000 [0x100f].
    > Bus 0, device 5, function 2:
    > USB Controller: Intel Corporation 82371AB PIIX4 USB (rev 1).
    > IRQ 11.
    > Master Capable. Latency=64.
    > I/O at 0xffe0 [0xffff].
    > Bus 0, device 5, function 3:
    > Bridge: Intel Corporation 82371AB PIIX4 ACPI (rev 2).
    >
    > Still, it is willing to run with RDTSC at 300MHz, 150MHz, and
    > 40MHz. (The last one in _extreme_ cases when CPU fan fails -- running
    > at 40MHz is better than cooking cpu).
    >
    > --
    > I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
    > Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org

    --
    <hpa@transmeta.com> at work, <hpa@zytor.com> in private!
    "Unix gives you enough rope to shoot yourself in the foot."
    http://www.zytor.com/~hpa/puzzle.txt
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