CPU Speed alternating

By Snuffy09 ·
What would cause my cpu speed to change back and foth? from 2.7ghz to 1.3ghz i can watch it change on cpuid. I reset CMOS, updated bios, tried different RAM. Still doing it. As far as i know its never done this before. could my PSU be failing?

CPU - AMD Athlon 64 X2 7750 Kuma 2.7GHz
RAM - Kingston HyperX T1 Series 4GB (2 x 2GB running at ddr2 800)


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It's what AMD call 'throttling back' ...

by OldER Mycroft In reply to CPU Speed alternating

All AMD chips have a 'PowerNOW' capability - this allows them to deliver maximum CPU power when it is required. When there is little need for full power, the CPU throttles back to a lower cycle speed.

It was originally designed for use in laptops to conserve as much battery power as possible.

As the years have gone on it has become de rigueur in all AMD CPUs.

When you were witnessing the cycle speed change, the calls made on the CPU by the system will have been changing simultaneously.

My laptop has an AMD Sempron 3000+ which runs at 1.8GHz. Frequently it will throttle back to 800MHz.

It's all perfectly normal. :)

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wow, ok

by Snuffy09 In reply to It's what AMD call 'throt ...

I just never noticed it before. I first noticed it when I looked at "my computer settings" then i monitored it with cpuid and watched it bounce around.

I have noticed a slower startup, loading my personal settings/starting services. the CPU should be using "power now" at that time shouldnt it?

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I think you are becoming needlessly over-concerned ...

by OldER Mycroft In reply to wow, ok

The time taken to change from throttling-back to full power is measured in milliseconds, therefore there is no discernible lag to speak of. Certainly no slowing-down that we mere humans would be capable of spotting.

If you "have noticed a slower startup, loading my personal settings/starting services" the likelihood is that you have created a setting that is causing the slowdown. It will all depend on what you have set to load at startup, whether it is available to the system at startup, and how many of these services you have invoked.

It will not be because of the 'PowerNOW!' technology.

As the old saying goes "It does exactly what it says on the tin" ~ or, in your case, the box that the CPU came in.

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haha ok then

by Snuffy09 In reply to I think you are becoming ...

I'll check some startup settings. Thanks for the Fast input :).

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cool n quiet

by Snuffy09 In reply to CPU Speed alternating

I disabled cool and quiet in the bios.

Now my cpu stays running at 2.7ghz

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What have you gained in the process ? ...

by OldER Mycroft In reply to cool n quiet

Other than a CPU fan that will die quicker due to the increased workload, a heavier load on your case fans, an increased level of wattage from your PSU, and lots of wasted CPU cycles when your system is idling.

Still, if you like a component thrashing around unneccesarily good on you! :)

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indeed, I think your better off to leave it on

by Slayer_ In reply to What have you gained in t ...

No need ot waste the electricity if it doesn't need it.

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Go 'GREEN' young man! { nt }

by OldER Mycroft In reply to indeed, I think your bett ...
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I thought about this also

by Snuffy09 In reply to What have you gained in t ...

im just glad im not going crazy, i must have had my bios set to have CnQ disabled before i upgraded my memory. I knew it stayed at 2.7 before.

I set my bios to defaults when I added new memory so it must have set my CPU back to run at cool and quiet. After that i started to notice the speed changes.

I have noticed my temps go up. I may change it back.

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