Strange boot

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Just build a new PC with Asus P5Q Pro motherboard and Intel E8400. First
thing that surprised me is that the cpu was only running at 2 Ghz, with a
default multiplier at 6x, which means that you have to manually overclock
the multiplier to 9x to have the pc running at nominal speed. Never seen
that before with Asus mobos...

Second thing is that when switching on the pc, it starts (not always) in 2
phases: fans start to spin for one second, then the PC stops, but restarts
again after one or 2 seconds and boots normally. After that, it's perfectly
stable and doesn't give any problem.

Could anyone explain what' s happening here or why?
Thanks in advance.

Re: Strange boot

ElJerid wrote:
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For the "double start", you can update the BIOS. Best place to look is
the Asus forum, because plenty of Asus board models have suffered at
one time or another.

(Check the forums for matching symptoms

   (A report, with no solution)

   (One poster here thinks it relates to a totally cold boot)

I looked in the BIOS release notes history, but "double start" is not mentioned.


The 6X versus 9X is EIST or Intel SpeedStep. When you have an
ACPI enabled OS, the OS monitors the degree of usage of the CPU.
If the CPU is loaded (say you're running Prime95 stress test), the
multiplier goes to 9X dynamically. When sitting in the desktop,
doing nothing, the multiplier drops back to 6X.

You can try disabling EIST in the BIOS.

You can go to the "Power" control panel, and select "Always On" power
scheme. The various power schemes may enable or disable EIST.

You can also use a utility, to force the multiplier. That is what
I did, since my motherboard initially didn't support EIST. I had
to use a hacked BIOS with my board, to get a working EIST.

You can use CPUZ, to check the current operating speed. It
updates every few seconds, and should reflect the current
operating conditions.

You can do a load test with Prime95. The multithreaded version
is here. (It is also available from .) When asked
to "join", select the stress testing option instead. Prime95 will
give you some idea, how stable your new build is. It should also
cause EIST to go to 9X, due to the 100% loading.

I have run into people with various kinds of systems, where
the system *insists* on staying at the low multiplier. The posters
were not able to identify what step fixed it for them...


Re: Strange boot


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One can hope, but I have a P35 board that still has this
problem... though part of the problem there is it's from the
now defunct Abit so no more bios updates.

Re: Strange boot

Somewhere on teh intarwebs kony wrote:
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My Asus P35 board (P5KE-WiFi/AP) has always had this 'problem' of
double-starting despite at least six BIOS updates from when I first got it.
When the power button is pressed the fans spin for maybe half a second, then
there is a two second pause before it starts properly.

It's never been a problem and I've always just considered it a feature of
this motherboard.


"Build a man a fire, and he`ll be warm for a day. Set a man on fire, and
he`ll be warm for the rest of his life." Terry Pratchett, Jingo.

Re: Strange boot

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That's normal.  The CPU is in power saving at low usage.
If you watch the CPU speed with CPU-Z, from,
you will see the multiplier switch between 6x and 9x as CPU
demand changes.

This can be changed in BIOS, but the best way is to use
the "Always On" power profile if you're running XP, or
with Vista, set the power profile to Performance, and
ensure that the CPU min and max settings are both at

Re: Strange boot

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I forgot to add; your CPU will run 2 to 3 deg C warmer at
idle, when at a constant 9x multiplier.

Re: Strange boot

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Thanks to all of you, this really reassures me about my mobo. I was afraid
the problem should or could be an announcement of  bsod...
And indeed, the problem (finally not a problem) only occurs after a cold
About the cpu speed at start up, I believe Paul's explanation is the answer.
After overclocking the cpu multiplier manually to 7.5 x, cpuz always
displays a speed of 3 Ghz.
Now it' s set at 9 x and the system runs stable at 3.6 Ghz.
Still, I don't understand why I have to set the multiplier at 7.5 to achieve
3 Ghz. Does that mean that the standard FSB speed should be 333 MHz ? If
yes, why is the system starting at 4000 x 6 instead of 333 x 9 (which makes
3 GHz for the cpu) ???

Re: Strange boot

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The E8400 FSB  spec is 1333MHz.  The clock speed is FSB/4, which
equates to 333MHz. Unless you've changed some other MB settings,
2.0GHz and 3.0GHz are the correct CPU speeds for multipliers of 6x and
9x repectively.  If a multiplier of  7.5x gives you a CPU speed of 3.0GHz,
then the FSB is set at 1600MHz.  Go into the BIOS and set the MB clock
at 333MHz, unless you intend to overclock.

Even if you maintain the CPU at stock 3.0GHz with a multiplier of  7.5x,
the motherboard is being overclocked by 20%, which will cause the
chipset to run hotter, even though that speed is in the Asus P5Q
Pro spec.

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