Intel ULV Processor Is Always Underclocked.

[erosenin]

Hi! My notebook has a i5 3427 ULV processor. It's rated to run at 1.8Ghz and under low load due to intel speed step it should decrease it's multiplier to be at a lower frequency. According to CPU-Z it's multiplier has a range of 8-27. But I have noticed that it always runs at multiplier=8(freq=0.77 Ghz). I thought the low speed was due to low workload but even on running Prime95 torture test. It keeps the CPU utilization at a constant 44% at 0.77 Ghz. The frequency and multiplier don't change as they should. I even changed the power setting of Windows to High Performance and it has no effect on it. Can this indicate a problem with my system, Any other tips on things I should check?

 

[ShintaiDK]

Does it stay at 800Mhz with AC plugged in when running Prime95 too? Also test the temperature with Realtemp while running Prime95.

800Mhz is the idle speed.

 

[mikeymikec]

I've recently encountered notebooks/netbooks where the active Windows power profile has the max CPU frequency set to say 50% of its capability.

Control Panel > Power Options > Balanced / whatever your default one is > Advanced > Processor Power Management

Check minimum and maximum. Defaults are 5% and 100% respectively. This allows normal CPU power saving features to be automatically utilised when the processor is idle, and for the processor to automatically crank up to full speed when necessary.

 

[erosenin]

Does it stay at 800Mhz with AC plugged in when running Prime95 too? Also test the temperature with Realtemp while running Prime95.

800Mhz is the idle speed.

Yeah, I ran the Prime95 torture test with AC plugged in. I am going to measure the temperature with RealTemp but when I looked at the temperature in Intel XT Utility it was between 60-62 Celsius.

 

[R0H1T]

Yeah, I ran the Prime95 torture test with AC plugged in. I am going to measure the temperature with RealTemp but when I looked at the temperature in Intel XT Utility it was between 60-62 Celsius.

Use cpuz or any other hardware monitoring utility(like aida64) to check for your processor's clock speed & also try to change it to high performance & see what happens cause unless someone has messed with your windows default power profiles the ULV processor will clock higher than what you're reporting. So just to make myself clear ~ it's the windows power profiles that determine how high or how far will your processor go, in terms of clock speed, when put under stress.

 

[erosenin]

I've recently encountered notebooks/netbooks where the active Windows power profile has the max CPU frequency set to say 50% of its capability.

Control Panel > Power Options > Balanced / whatever your default one is > Advanced > Processor Power Management

Check minimum and maximum. Defaults are 5% and 100% respectively. This allows normal CPU power saving features to be automatically utilised when the processor is idle, and for the processor to automatically crank up to full speed when necessary.

Hmm. in my primary power profile. It's max(50% - Battery, 100% - Plugged in) and in the high performance one max(100% - Battery,100% - Plugged in). Since I did the tests while plugged in It should have increased the multiplier. Also, I tried changing the profile to high performance but nothing changed.

 

[erosenin]

Use cpuz or any other hardware monitoring utility(like aida64) to check for your processor's clock speed & also try to change it to high performance & see what happens cause unless someone has messed with your windows default power profiles the ULV processor will clock higher than what you're reporting. So just to make myself clear ~ it's the windows power profiles that determine how high or how far will your processor go, in terms of clock speed, when put under stress.

CPU-Z is also reporting 798 Mhz and I did the Prime95 test on the high performance power profile.

 

[ShintaiDK]

CPU-Z is dynamic, just to make sure you look at CPU-Z while running Prime95.

You might also check your BIOS for any settings. Might be set to some extreme battery profile there.

 

[R0H1T]

CPU-Z is also reporting 798 Mhz and I did the Prime95 test on the high performance power profile.

Can you post the screenshot of cpuz & task manager, side by side, when you're running the Prime95 test ?

 

[erosenin]

CPU-Z is dynamic, just to make sure you look at CPU-Z while running Prime95.

You might also check your BIOS for any settings. Might be set to some extreme battery profile there.

yeah, I checked the CPU-Z application while running the test.
I would have a look at the BIOS setting.

I would like to note that when I start the notebook, it's processor speed is initially dynamic and stays around 1.8-2.7 for 3-4 minutes and then it underclocks and never increases it's multiplier.

 

[erosenin]

Can you post the screenshot of cpuz & task manager, side by side, when you're running the Prime95 test ?

Surprisingly it now reports the temperature as 73 Celsius

 

[ShintaiDK]

It sounds like you simply got an application or setting that prevents it due to being in some kind of extreme energy saver mode.

Temperature that much below throttle on a laptop is essentially irrelevant due to fanspeed control.

 

[erosenin]

It sounds like you simply got an application or setting that prevents it due to being in some kind of extreme energy saver mode.

Temperature that much below throttle on a laptop is essentially irrelevant due to fanspeed control.

Yeah, I will check BIOS.

 

[Piroko]

There are some Notebooks where the Intel EIST is doing weird stuff, e.g. there were some Yogas (but only some), where an activated EIST meant it would always run at 800 Mhz in tablet mode.

 

[erosenin]

There are some Notebooks where the Intel EIST is doing weird stuff, e.g. there were some Yogas (but only some), where an activated EIST meant it would always run at 800 Mhz in tablet mode.

Is there any fix for that?

 

[Piroko]

Yeah, turning EIST off in the bios removes the manual cap.
You can also uninstall the Intel EIST driver in Windows, but Win 8.1 likes to automatically reinstall it and disabling the functionality in the bios will also disable that driver anyways.

 

[Techhog]

I wouldn't be shocked if the manufacturer did this intentionally for battery and power usage marketing. :/

 

[unclewebb]

Leave EIST on. The Intel U and UM CPUs are low power CPUs. They have a feature called TDP Level control so that a manufacturer can have them switch between the default TDP power level to a high TDP power level or down to a low TDP power level. In the low level, the default multiplier is 8 so it's possible that your CPU is locked in this state.

For these CPUs, you should start by using ThrottleStop. Post a screen shot of the Power Limits window (TPL button). That window contains information about what the manufacturer has done with your CPU. At high load or when on battery power, it's not uncommon to lock the CPU into Level 1 which has the lowest TDP and the lowest default multiplier.

What this means is that a 3427UM CPU can run vastly different depending on what device it is installed in and what decisions a laptop or tablet vendor decided to make in the bios.

Anyway, give ThrottleStop a try, post some screen shots and I will try to help you figure out what's going on with your CPU and if there are any possible fixes. Intel has given unlimited control to manufacturers that use their low power CPUs.

ThrottleStop 6.00
http://www.thedigitalhq.com/downloads/

 

[Piroko]

I wouldn't be shocked if the manufacturer did this intentionally for battery and power usage marketing. :/

I doubt it. Or at least I doubt that it is done intentionally from the engineering department (the marketing guys might do it though..). Ivy Bridge locked to 800 MHz will drop frames and stutter on games and video playbacks. It's very easy to notice how slow the system is, even in your local Best Buy.

edit: rechecked the setting that I had in mind, the issue with Yogas was the Intel Dynamic Platform & Thermal Framework driver running wild, not the EIST itself. The DPTF simply locked it to 800 MHz as soon as you put it in tablet mode. Disabling the DPTF only altered this behaviour as far as I'm aware.

 

[erosenin]

Leave EIST on. The Intel U and UM CPUs are low power CPUs. They have a feature called TDP Level control so that a manufacturer can have them switch between the default TDP power level to a high TDP power level or down to a low TDP power level. In the low level, the default multiplier is 8 so it's possible that your CPU is locked in this state.

For these CPUs, you should start by using ThrottleStop. Post a screen shot of the Power Limits window (TPL button). That window contains information about what the manufacturer has done with your CPU. At high load or when on battery power, it's not uncommon to lock the CPU into Level 1 which has the lowest TDP and the lowest default multiplier.

What this means is that a 3427UM CPU can run vastly different depending on what device it is installed in and what decisions a laptop or tablet vendor decided to make in the bios.

Anyway, give ThrottleStop a try, post some screen shots and I will try to help you figure out what's going on with your CPU and if there are any possible fixes. Intel has given unlimited control to manufacturers that use their low power CPUs.

ThrottleStop 6.00
http://www.thedigitalhq.com/downloads/

Hey, thanks for looking into it. Here is the screenshot from ThrottleStop.

Edit:

Hey, I played with a few settings and when I changed the multiplier to 18 through that tool. It changed the multiplier of the CPU in dynamic levels of 24-26. However even when I turned off it. It stayed at that level. So, I changed it back to 8 through the tool. Have I modified some internal setting. If so, how to reset it to the previous state.

 

[erosenin]

I doubt it. Or at least I doubt that it is done intentionally from the engineering department (the marketing guys might do it though..). Ivy Bridge locked to 800 MHz will drop frames and stutter on games and video playbacks. It's very easy to notice how slow the system is, even in your local Best Buy.

edit: rechecked the setting that I had in mind, the issue with Yogas was the Intel Dynamic Platform & Thermal Framework driver running wild, not the EIST itself. The DPTF simply locked it to 800 MHz as soon as you put it in tablet mode. Disabling the DPTF only altered this behaviour as far as I'm aware.

Hey, thanks for looking into it but that service is not running on my machine. So, I guess that's not the problem.

 

[unclewebb]

Here's an example of what a UM CPU looks like when it is in the Level 1 TDP mode.

http://img853.imageshack.us/img853/6664/cl0d.png

Here is the same CPU, same load with the TDP in Level 0.

http://img843.imageshack.us/img843/29/v4ph.png

And finally, here's an example of the same CPU in Level 2 with the Power Balance set to favor the CPU.

http://img189.imageshack.us/img189/5348/mh9d.png

That third pic shows a completely different CPU compared to when this CPU is in Level 1 but the pics are all from the exact CPU. There has not been a lot of talk in the forums about what these UM CPUs are capable of.

Edit: Start by disabling BD PROCHOT and see if that helps your multiplier. Your CPU only uses Level 0 and Level 1.

 

[unclewebb]

ThrottleStop should have the Set Multiplier value set to 28T. The T stands for Turbo since your CPU requires Intel Turbo Boost to use that multiplier when a single core is active. Post a screen shot or two while testing. It sounds like you are starting to figure out this problem.

Low power CPUs spend most of their idle time in one of the deep low power C States like C6. When in this state, you don't have to worry about what the multiplier is. In C6, the CPU drops the voltage and power consumption for that core to virtually zero so a high or low multiplier doesn't make any difference. Some people have a hard time understanding this concept. Here's some light reading about why a high multiplier is best.

Power Optimazation - A Reality Check
http://www.cs.berkeley.edu/~krioukov/realityCheck.pdf

 

[erosenin]

Here's an example of what a UM CPU looks like when it is in the Level 1 TDP mode.

http://img853.imageshack.us/img853/6664/cl0d.png

Here is the same CPU, same load with the TDP in Level 0.

http://img843.imageshack.us/img843/29/v4ph.png

And finally, here's an example of the same CPU in Level 2 with the Power Balance set to favor the CPU.

http://img189.imageshack.us/img189/5348/mh9d.png

That third pic shows a completely different CPU compared to when this CPU is in Level 1 but the pics are all from the exact CPU. There has not been a lot of talk in the forums about what these UM CPUs are capable of.

Edit: Start by disabling BD PROCHOT and see if that helps your multiplier. Your CPU only uses Level 0 and Level 1.

Disabling BD PROCHOT didn't help. Also, many of my options in the power window are disabled. Even the TDP throttling button. Is that due to BIOS settings?

 

[unclewebb]

Yes. If the bios sets the lock bit then software can not adjust it. The only way around this is with a modified bios. I thought BD PROCHOT might be causing the problem with your multiplier but it looks like it was just the Set Multiplier value was not set correctly. Not sure why.

Your screen shot shows that the Power Limit Register has been Locked so that blocks user software from adjusting the TDP limits. You shouldn't need to worry about this now that the multi is working.

When Turbo Boost is being used, the multiplier will rapidly vary depending on whether 1 or 2 cores are active. You can look in the TRL window. It will show you the maximum multiplier depending on whether 1 or 2 cores are active. The multiplier is also locked. This is only adjustable in the XM mobile CPUs or some of the upper level Core i7 CPUs. It is also adjustable in the desktop K series.

Edit: I just noticed your CPU model number. It is actually a Core i5-3337U. These have a default multiplier of 18 when in Level 0 and a maximum turbo multiplier of 27.

http://ark.intel.com/products/72055/Intel-Core-i5-3337U-Processor-3M-Cache-up-to-2_70-GHz?q=3337

The Specification box in CPU-Z shows the actual model number that Intel burned into the CPU at the factory.

Any multiplier higher than 18 requires Turbo Boost and as soon as you start using Turbo Boost, the multiplier will start rapidly moving in ThrottleStop and within the CPU for that matter.