Why does my multiplier change thread.

RJC · 4 Feb 2009 at 20:21

I thought I have a go at a sticky regards Intels speedstep which catches a few people out

Intel speedstep reduces the cpu's multiplier when idle and raises when required, this helps to conserve power when idle and can help with noise and heat.

Most people notice this when running programes like CPU-Z, this is not fault with the cpu or motherboard.

Intel speedstep can be disabled if required through the motherboards BIOS.
You will need to look for C1E (Enhanced Halt State) & EIST (Enhanced Intel Speedstep® Technology), but some boards may use different names/terms, checking the manual should help.

Keeping speedstep enabled is down to personal choice. I have mine enabled and not had any stability problems.

Link to wikipedia: Clicky

If the mulitiplier does not change when stressed it may be the BIOS has not detected the multiplier correctly and manual change may be required or a BIOS update if the CPU is a new edition - You will need to check the manufacturers web site for cpu support and how to update the BIOS.

Hopefully the above can be of use to people and that I have not made a complete fool of myself

Intel Turbo Boost:

This allows the cpu to increase the multiplier when the cpu is stressed above it's normal default setting, this gives the user a performance boost when needed.

When Overclocking some people keep this enabled to give them a performance boost when needed, I have mine disabled and have cpu run at 4ghz with speedstep enabled.

Different cpu models have different levels of Turbo Boost, linked below is information from Intel which explains better than I can, also there is a link which you can download to check if your Turbo boost is enabled and working.

http://www.intel.com/technology/turboboost/

http://www.intel.com/support/processors/sb/cs-029908.htm

https://downloadcenter.intel.com/download/25994/Intel-Turbo-Boost-Max-Technology-3-0

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The Above also goes for the new Sandy Bridge chips as well.

Programs which can be of used:

CPU-Z - Shows cpu info and multiplier settings:

http://www.cpuid.com/softwares/cpu-z.html

Prime - Use for testing cpu stability and to ensure the multiplier does increase when speedstep is enabled.

http://www.mersenne.org/freesoft/

Audigex · 4 Feb 2009 at 20:37

The instability can come in when overclocking. Most overclockers will have found certain bus-multiplier combinations which are instable even though either will work when raised slightly.

In a few rare cases, the maximum achievable clock speed's FSB will disagree with the Speedstep multiplier. Eg 9x500 works fine, but 6x500 is one of those trick-shot combinations which are unstable.

If you find your speedstep makes your system unstable, try reducing your overclock even a small amount and see if you can hit a combination which is stable with both multipliers.

linktoinsanity · 5 Feb 2009 at 10:42

I had to disable this option in mine. I found out that Red Alert 1 (yeh I know it's old

) crashes when the speed changes. There are definately some problems in the programming there. (Hyperthreading/multiple cores and speedstep all crash the game!)

CurlyWhirly · 6 Feb 2009 at 20:34

RJC said:
I thought I have a go at a sticky regards Intels speedstep which catches a few people out

Hopefully the above can be of use to people and that I have not made a complete fool of myself

Not at all as I was one of the people that was caught out when I posted a thread about it a few days ago

(mind you I am new to modern processors as I've only recently upgraded to a modern processor - Q9650 with my old CPU being an Athlon XP3000+

)

I've recently discovered that you can see the CPU clock speed change (in real time) if you minimise CPU-Z to the Windows taskbar!

Personally I think that Intel SpeedStep is a great feature as long as it doesn't cause problems when overclocking for example.

RJC · 6 Feb 2009 at 20:51

CurlyWhirly said:
Not at all as I was one of the people that was caught out when I posted a thread about it a few days ago (mind you I am new to modern processors as I've only recently upgraded to a modern processor - Q9650 with my old CPU being an Athlon XP3000+ )

I've recently discovered that you can see the CPU clock speed change (in real time) if you minimise CPU-Z to the Windows taskbar!

Personally I think that Intel SpeedStep is a great feature as long as it doesn't cause problems when overclocking for example.

Quite a nice step-up there :cool:

, CPU-Z is a handy little tool to use

Hopefully this will help people in the future, enjoy your new pc

ben_moore34 · 27 Feb 2009 at 09:55

I have speedstep enabled on my E6300 and have noticed that in CPUz
The speed changes from 1866 MHz to 2314 MHz when Prime is performing tests.
However
If I try running loads of things at once the speed seems to stay at 1866. Is this because nothing is putting too much stress on the CPU? I'd have thought that it would have gone up a bit when 3 applications, some videos and a game are all running at the same time.

CurlyWhirly · 27 Feb 2009 at 19:56

ben_moore34 said:
I have speedstep enabled on my E6300 and have noticed that in CPUz
The speed changes from 1866 MHz to 2314 MHz when Prime is performing tests.
However
If I try running loads of things at once the speed seems to stay at 1866. Is this because nothing is putting too much stress on the CPU? I'd have thought that it would have gone up a bit when 3 applications, some videos and a game are all running at the same time.

I'm not sure about your E6300 but with my Q9650 the CPU runs at full speed (i.e. a 9x multiplier) when CPU usage hits around 40% when SpeedStep is enabled.

Kennysevenfold · 2 Jan 2010 at 20:07

This should be Stickied tbh.

tbh · 4 Jan 2010 at 01:37

Kennysevenfold said:
This should be Stickied tbh.

Probably, but then most people don't read stickies anyway...

SMAndy · 5 Jan 2010 at 08:59

This works for AMD Cool'N'Quiet too. It works in exactly the same way. They can both be turned off, and on some Motherboards (Gigabyte i think being one...) AMD Cool'n'quiet has issues, and doesn't work as it should do. Lots of AMD peeps turn it off to get a stable overclock. I turned my Cool'n'quiet off because i don't want to have these problems... and my idle temps are fantastic (25°C max) that I won't get any benefit of longer life or anything to worry about it.

AMG · 5 Jan 2010 at 11:29

too save power, and so the cpu runs cooler, it can cause problems if over clocked systems through

xen_ · 5 Jan 2010 at 15:59

Speed step is a great feature, I cringe when I see the advice of turning it off (when no overclocking is involved), I've even found it to be excellent with overclocking so it's worth leaving on if even you do overclock unless it causes instability, no need for 4GHz just to browse ocuk

.

mjones1 · 8 May 2010 at 17:02

bump.

setter · 9 May 2010 at 04:57

This definitely needs to be made a sticky, this question comes up so often.

RJC · 9 May 2010 at 08:46

Added some information regards Turbo Boost

iNPUt · 9 May 2010 at 17:20

Also there has been some encounters with new Coretemp 0.99.6 reporting frequency falsely as the lowest multiplier which has confused some people.

Check this thread for more info. Reverting back to 0.99.5 fixes this.

RJC · 16 Mar 2012 at 09:07

Thought I bump this thread, I have added a little more info, but if anyone has any more please post

edscdk · 16 Mar 2012 at 09:11

ben_moore34 said:
I have speedstep enabled on my E6300 and have noticed that in CPUz
The speed changes from 1866 MHz to 2314 MHz when Prime is performing tests.
However
If I try running loads of things at once the speed seems to stay at 1866. Is this because nothing is putting too much stress on the CPU? I'd have thought that it would have gone up a bit when 3 applications, some videos and a game are all running at the same time.

look in task manager if the CPU usage is high and the MHZ low you have an issue..

video will probably be decoded by the GPU, applications usually do very little... (email word etc)

Ghøst · 13 Apr 2012 at 17:15

Why does my CPU-Z multiplier fluctuate between 45 & 46 when it has been set to 46 in the BIOS the fluctuation starts when the CPU is put under full load in Prime95.

EIST is disabled in the BIOS & Vdroop set to auto.

*Edit

Even more interesting the multiplier fluctuation only occurs when doing the small FFT test in Prime95 when running the same test in blended mode the multiplier stays locked to 46 as expected.

It looks like my CPU is being throttled back perhaps however core temps are mid to high 60's VRM temp is being actively cooled and sitting 61 degrees.

Strange brew I wonder if the Vdroop has something to do with this.....

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So after much experimentation I'm fairly confident that Vdroop / LLC was at least a partial cause of this issue as I've been able to eliminate the fluctuations on Vdroop levels 3 & 4 out of the 7 available settings in the BIOS.

I'm still confused however as to why these multiplier fluctuation would occur apparently when LLC is applied either very loosely or very aggressively.....

Sampsy · 7 May 2012 at 17:34

I am feeling bored so may twiddle with my CPU a little more. However my CPU multiplier still fluctuates between 16 & the target when idle, even though C1E & Speedstep are disabled. When at load the multiplier does not fluctuate, although the vcore will, supposedly due to the fact that I am overclocking with offsets, but this is not a problem. What could be causing this? Using a 2500k on an asrock z68 extreme 4 (non gen3).