Mobo mulitplier unstable, Why?

OkieDave

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Dec 27, 2009
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Hi ya'll, I lurk these forums quite a bit and it's my "go to" source for tech info, for sure!

I'm running Win 7 Pro on a Gigabyte GA-EP45-UD3L mobo, with a Q9550 and 4Gb RAM, DDR2-800 (5-5-5-15 @ 400 MHz).
Had some strange events the last week, of system slow-downs, even one or two lock-ups. Not BSOD's, just locked up! Generally telling me that Windows Explorer was not responding.

This got me looking into my BIOS and become somewhat familiar with Real Temp, CPU-Z, & Core Temp. I have all 3 because I noticed that the CPU Freq multiplier, which is set to 7.5, would randomly change to 6.0 or 6.5! To my knowledge this number should be steady & match the number I set in the BIOS. So, I grabbed another test program, and yet a third to check one against the other. Not such a good idea, I guess, since it got me to questioning even more.

With all 3 of these running on the desktop, that's when I see the fluctuating multiplier. However, the minute I open Firefox, 2 of the 3 programs give me the true reading of 7.5, resulting in 3Ghz system. CPU-Z is the one that varies with Firefox open. It will vary from 7.5 - 6.0. I have watched Core Temp & Real Temp now for a while and they seem to display 7.5 steadily.

So after that description, here are my
Questions:
1. Is it normal to see a change in the multiplier, that is entered in the BIOS?
2. Is it normal to have 3 programs that offer up different info?

Thanks for any help you can render!
OkieDave
 
Solution
Check your CPU temps and make sure all of your fans are working. It sounds like your CPU is throttling itself down to reduce heat.

to answer your questions.
1. most modern CPU's can throttle down their multipliers to protect themselves form over heating. lower multiplier = lower power usage = lower temps.
2. It's not impossible for 3 different programs to display different info. it depends upon how it gets its information. CPU-Z reads the System info directly from the mobo at regular intervals so that's why it is showing the varying multiplier. I see my system do the same thing with the cpu voltage under load vs no load.

JKatwyopc

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Check your CPU temps and make sure all of your fans are working. It sounds like your CPU is throttling itself down to reduce heat.

to answer your questions.
1. most modern CPU's can throttle down their multipliers to protect themselves form over heating. lower multiplier = lower power usage = lower temps.
2. It's not impossible for 3 different programs to display different info. it depends upon how it gets its information. CPU-Z reads the System info directly from the mobo at regular intervals so that's why it is showing the varying multiplier. I see my system do the same thing with the cpu voltage under load vs no load.
 
Solution

OkieDave

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Dec 27, 2009
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Core temps are 42, 42 , 39, 39, so I don't think I have a temp issue, but I understand the throttling thing. I have a very large fan cooled heatsink on the 9550, and directly to the rear of that is the exhaust fan. Soooo....

Hey JKat, thanks for the explanations. I may pursue this some more tomorrow, but since the system seems to be solid currently, I'm gonna "test drive" this week and see how things go.

Thanks again!
OkieDave
 

OkieDave

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Dec 27, 2009
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Just to close this out....

There is/was NO heat related issue at all. However, the "throttling" effect that was mentioned did get me thinking about just what could cause this eratic behavior. Bingo! It is a BIOS setting that tells the CPU to throttle back when not being called upon or stressed. Sorry, I forget what it was called now. But Google was my friend and led me to it! So, I am sure Goggle can do it for you too.

Later,
OkieDave