U300s- Maximum CPU Frequency Locks at 44%

Hello Lenovo Forum,

I am having an issue with the U300s Ultrabook.

The machine will randomly downclock and lock it self to 44% maximum CPU Frequency.

I have tried reinstalling power manager, uninstalling power manager, checking the temperature of the machine and more and can't seem to get this machine to stop. (PS: I have the latest BIOS)

At first It seemed to happen when only plugged in, but as I sit here I notice it is happening on battery too.

Any help would be much appreciated as I am at wits end of what to do.

Thanks.



-Mike

 

I have the orange i7 256gb U300s just like you (since December 2011), but I have never had the problem you mention. Major bummer... maybe you should RMA? Where did you purchase yours?

 

I received mine about a week ago.

When you open your Resource Monitor what is the maximum cpu frequency listed?

 

My max frequency fluctuates around 90% to 110% on balanced performance settings.

 

My Max Frequency goes up to 100%
I am not seeing any issues here - I have a 2 week old i7

 

Hmm... my CPU randomly locks at 44%.. sigh. Time to call support unless you guys can suggest anything else. I wish I could "reimage" the BIOS, but it won't let me since it's already the latest version.

 

Mine does do this. It's a core i5 1.60, which generally sticks at 800MHz most of the time (100Mhz x 8 multiplier). Strangely, if I unplug the power cord, it'll rocket up to 20 multiplier (bring it up to 2GHz!), but only on certain power profiles (Energy Star is one).

Balanced will not ever go above 8x multiplier, which is a pain in the ar$e. I'm currently uploading a video to YouTube explaining the issue (which I am sending to Lenovo UK support). I've already got them to send it to the engineers to validate, but the addition of video proof should help the case. I'd urge you all to try this out and see whether you also have the same issue. Maybe with a few people complaining of the same problem, it'll get escalated quicker.

 

Guys try this:

Right click Computer > Properties > Performance Information and Tools > Adjust Power Settings > Click Change Plan Settings > Change Advanced Power Settings > (In the windows that opens) Scroll down to Processor power management > Click on Minimum processor state and set it to 100. Do the same for Maximum processor state

 

Video here:
U300s power management issue - YouTube
Recorded on my rubbish iphone, so it looks TEEEERRRIBLE.

Best to watch it at 1080p fullscreen, otherwise you won't be able to see the clock frequencies

Update:
After katalin_2003's suggestion, I thought I'd play with the settings to see whether I could get it to work as it should.
What I did:
Opened Lenovo energy management software
Selected "Detailed settings"
Went to the "system" tab
Under "When running on AC power", I moved the 'Maximum CPU Speed' slider from 'Auto' to 'High'.

WOW! It works like it's supposed to! At least so far it does
I'll keep testing to see whether this has fixed it and post back

OK, made the changes to both Energy Star and High Performance profiles and that seems to have made things a whole lot better.

This hasn't fixed the issue though, as the "Auto" setting is still somewhat broken. Why, on a 'High Performance' profile would the 'Auto' setting not be high performance?? And even then, why would it only be an issue when plugged into the mains?

[hopefulface]I've sent the video off to Lenovo now so hopefully should hear back in a few days time[/hopefulface]

 

Thanks Chris!

I'll set mine to High Performance also and i'll see what happens.

Don't forget to update us! Thanks!

 

Hmm.... Now that *is* weird......

After running on my modified "Energy Star" profile (ie. Maximum CPU set to High when plugged in), I decided to do a bit more digging. I then switched it back to 'Auto' to see what would happen. Guess what? It's actually started working almost as it's supposed to!!!!

Video to follow

GAAAAHHHH!!

I was about to record and upload another video to Youtube showing how it was 'working'. Alas, when I started recording it with my phone, it was stuck at 800MHz all the time :-(
This time, it was stuck at 800 on battery and when charging. I seriously don't understand this....

 

But it does work on High performance correct?

 

I'll check in a minute or two

OK, here's a perfect example of the issue with the Energy Star profile:
Energy star pt1 - YouTube

And here is a video of it working perfectly!
Energy star pt2 - YouTube
The only thing I did differently, was to leave the laptop on and plugged into the charger for 10 mins. Went back and tried to repeat the same issue, and it just worked.

Why oh why oh why????

 

Excellent I'll pass this onto the Lenovo team.

Thanks for your help.

 

Michael, you and Chris are doing a fantastic job here!

Some random thoughts / questions on this...

1) Are you consistently testing with the same level of battery charge and AC plugged in? I ask because if you max out the power draw, I wonder if the battery is at a lower level if the voltage drops a bit as you draw higher amounts of power and the system sees this and throttles back?

2) What other benchmarks have you run and is there a difference in whether your benchmark is running single thread or multi-threaded ?

On some of the ThinkPad W520 power / performance issues we were working through last year, we noted that the quad cores could have a lowered (capped) clock rate when you engaged all the cores, while turbo-boost kicked in and ran higher clock speeds with single threaded tests that only engaged 1 core. Taxing graphics with furmark or other benchmark also reduced the clock speed to keep things under the TDP.

3) While you haven't mentioned any overheating, have you run a temp monitoring package and tracked CPU / GPU temps vs your clock rate and testing to see what is going on?

Generally power or temp limits are what may cap / throttle the CPU. Or, there is just quirk in BIOS or Power Management. Appreciate all your observations and data!

Mark

 

This had crossed my mind, but I've not done anything to investigate it yet.
Maybe that's the reason why the problem sort of 'went away' once I'd left the laptop charging for a while?

In each case, I did the following:
1. I simply monitored the clock rate when simply doing standard tasks in windows (ie. all cores were used, handled by the windows task scheduler). Things such as launching applications, or even just sitting at the desktop with a few Chrome tabs open, etc. In this case, I'd expect to see the clock frequency sat mostly at 800MHz, but bounce around a little depending on the workload.
2. Running 100% CPU on all logical cores using OCCT
3. Running 100% CPU with the 'all logical cores' box unticked. (ie. not purely single threaded as such, as the CPU has hyperthreading and lists itself as having 4 cores in task manager, therefore the windows task scheduler will move the thread about as it sees fit).

Yep, I remember that on the X220 - the reason I didn't buy one.

However, to assuage concerns over this, I am running CPU tasks solely - no GPU in the mix at all.

Yep, I thought of this too. Generally, the fan is pretty good at keeping the CPU cool, and returns to normal temps (somewhere between 32 and 37 degrees C) within a few seconds of running each 'benchmark'. However, be aware that my 'benchmarks' consist of either doing nothing but opening applications (ie. no real temperature cost) or running 100% for 20 seconds at most (again, very little heat build up in that time).

I'll keep looking and get back to you with my observations
Breame

OK, testing time. I'm going to try the 'High Performance' profile (battery is on 60%, CPU is 35 degrees C). Making sure to leave the max CPU setting in the Energy Management software at 'Auto' levels for both AC power and battery.

I'll then let the battery run down to a much lower state and try the same test again.

OK, set to High Performance profile in the Energy Management software. Auto settings for CPU speed on both.

When on battery power, the clock hops about as it's supposed to when on Windows desktop doing standard tasks. When taxing the CPU 100%, it ramps up to 2GHz (turbo frequency) as it's supposed to.

Plugging in the AC adapter forces the clock speed to be locked at 800MHz. That happens on the desktop and also when running 100% CPU.

Here's the interesting bit:
Unplugging the AC adapter! The clock speed is locked at 800MHz still. Won't go above that speed at all.

I'm going to leave it unplugged for a few minutes to see whether it 'recovers'

Answer: nope

I'm going to switch to 'Energy Star' profile to see whether it'll get it working again (both settings set to Auto)

(current battery level 56%)

Answer: nope

Next on the agenda - change Auto settings to High performance for both AC power and battery (still Energy Star)

Answer: nope
STILL stuck at 800MHz

OK, next to try is to leave the laptop plugged in and charging for a few minutes to bring the battery level above 60% (+setting Energy Star profile back to Auto again). I have a suspicion that it might be battery related?

P.S. I've also noticed something weird about the clock speed directly after resuming from sleep. If I get the clock speed in it's locked state, then put the laptop to sleep and wake it up, it appears to start working again.

Investigation to follow

Answer: getting the battery above 60% doesn't make a difference. In fact, the laptop is now in a state where it is entirely stuck at 800MHz.
Video evidence here:
U300s locked power management pt1 - YouTube

Edit: Also tried this same thing but with CPU maximum clocks set to High instead of Auto

There you go - as soon as you resume from sleep, auto clock adjustment will work temporarily (when powered by battery).... Until you plug in the AC adapter, then it'll get locked at 800MHz again.
U300s locked power management pt2 - YouTube

Probably the last update for today:
Since the last video, I left the AC adapter in, and the battery has now reached 100% charge. Went back to check the CPU clock again, and it's functioning perfectly again. This works on both AC power and battery (using Energy Star profile).

My guess is that it MUST be something to do with the battery charge level. Either that, or it's something to do with the energy management needing a set amount of time where there is no user input to 'settle down' before it's able to adjust core frequency.

..or something :-/

 

OK, I've been trying to figure out exactly how the energy management operates on battery power, and I think I might have a decent idea.

What I did:
1. Set the profile to Energy Star
2. Set the CPU clocks to 'Auto'
3. Left the AC adapter unplugged
4. Kept an eye on the CPU frequency to see when it fluctuated and when it locked itself to 800MHz
5. Allowed the battery to drain down to 8%
6. Plugged the AC adapter in
7. Kept an eye on the CPU frequency to see when it fluctuated and when it locked itself to 800MHz
8. Allowed the battery to charge up to 87%

OK, so first set of conclusions:
1. The CPU frequency moved around just fine (800Mhz/900MHz/1100Mhz/etc) throughout the time when the laptop was on. The frequency adjusted according to workload when on battery power.
2. When the CPU hit 100%, turbo kicked in.
3. As soon as the battery reached 10%, the frequency was locked to 800MHz to conserve battery.
So far, all of this works exactly as expected.

4. As soon as the AC adapter was plugged in, the frequency was locked to 800MHz.
5. Once the battery charge reached 80%, the frequency became unlocked again and would bounce around according to workload.
6. When the CPU hit 100%, turbo kicked in.

To Summarise:
--------------
When running on battery:
1. Between 100% and 11% battery charge, the core clock will hop about with no issues
2. Battery charge of 10% and under means that the clock is locked to 800MHz

When running on AC:
1. Between 80% and 0% battery charge, the core clock will lock to 800MHz
BAD LENOVO [points at laptop and hits lenovo very gently on the nose] BAD!
2. Battery charge of 81% and over means that the clock is able to hop about with no issues
3. If the battery is between 80% and 0% and you plug the AC adapter in, it can often lock the CPU to 800MHz - meaning when you come to unplug it and return to battery power, it remains on 800MHz (more investigation to follow on this one, as I'm not 100% sure about this just yet).

I have repeated the same test but with the High Performance profile. this time I modified it so that the Max CPU frequency is 'High' instead of 'Auto'.

On first glance, it appears to behave in exactly the same manner as High Performance on Auto.
And also the same as Energy Star on Auto.

 

Hi Chris. Here is my update:

After tinkering with the machine I decided to have the motherboard replaced, so Lenovo sent out a motherboard. It was thrown into the machine and so far the machine works a ton better.

It seems to work perfectly all the time and I notice the 44% lock sometimes happens (really rare) when coming out of sleep mode, but it goes away within a couple of minutes. I will keep an eye out to see what happens, but it seems the new motherboard did the trick.

My only other idea if the machine still fails to work would be an issue with the fans, but both seem fine and I'm not given an error about a fan error when booting so I doubt it is that.

On the negative side after the Lenovo technician left my house the fan started making a loud buzzing noise... I opened the laptop and fixed the fan, but snapped a piece putting everything back together. Luckily thanks to accidental damage the part should arrive tomorrow and everything will be good as new. (I will note that I had problems with the IdeaPad support in IDing the product... on a positive side the two wrong parts they sent out I get to keep, so if it ever breaks for some reason I am in luck!)

Mixed support experience so far and definitively below the ThinkPad support, but everything seems to be running steady now.

The U300s is still my #1 ultrabook recommendation for Windows PC fans.

I would say have your motherboard replaced Chris. It seemed to do the trick for me as I only notice the 44% sometimes for a very short period when coming out of sleep mode. I'm also getting a new AC adapter in the mail tomorrow from Lenovo to see if the adapter may be the cause, but so far I think it is the motherboard.

PS- Testing the issue in different OS environments or with out the Lenovo software have shown it is not the software on the computer (aka auto, high, etc) that seems to make the difference, but something entirely in the BIOS.

I'll keep an eye out and I'll update you if the situation changes.

-Mike

 

UPDATE --->

That should say it all. New motherboard and AC Adapter, but same problem. I did unplug the machine after it reached 80% and plugged it back in which let it start working again, but this should not be an issue. I have a feeling that a similar BIOS was used between the X1 and this machine as the X1 fast charges to 80%... I feel that these machines might be trying to do the same although they are advertised to fast charge to 50%. Still this should not be an issue. It seems like we need a BIOS update. Question is... will we get one with so few people showing the issue or will we be swept under the rug?

 

Hi ChrisBreame

I have the U300S with the core i5 - 1.6ghz processor.
I am having EXACTLY THE SAME issue as you - cpu frequency lock at 50%
I have also updated the BIOS to the latest version from the Lenovo website - it hasn't helped at all.
Have you managed to find a solution for this ?

Thank you

 

Hi, This is an issue with the current BIOS. I have been told by Lenovo that a fix is in the works.

For now the CPU locks it self when there is a battery charge between 0-80% AND the unit is plugged in. At the moment the only thing you can do is unplug and replug in the unit after it passes the 81% mark.

I will post when a new BIOS is available.

 

Hi Marcham93

Thank you for your response. Appreciate it.
I will keep an eye on this thread for your post when the new BIOS is made available

 

I've not heard back from Lenovo support about this, so it's probably time I chased it.

I agree that it's most likely due to the fast charge feature - maybe there is limited current available whilst fast charging...? Or there is an artificial lock put in place to ensure that the battery charges as fast as possible. No matter, apart from this annoyance, the machine is simply fantastic, though I'm glad that we're getting a BIOS update to mitigate the issue as much as possible.

 

Just to update you guys.

A new BIOS is in the works... expect it in the coming weeks.

I will post when it is out.

-Mike

 

The new BIOS is available on the Lenovo Support site.

Link: Lenovo Support - Drivers & Downloads


I haven't tried it as yet. Will do so later.

I downloaded and installed the new BIOS (version43), from the Lenovo support website.
I followed all the instructions as per the Lenovo support website precisely.

THE PROBLEM REMAINS !!!

If the battery level is less than 80% (for example 72%), and the charger is plugged in the CPU Frequency locks at 49%.


Lenovo are USELESS !


The Lenovo Ideapad U300S is nothing more than an expensive piece of junk !!!




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Here is my update:

I updated the BIOS to v43 and the underclocking issue seems to be fixed.

Also my Windows 8 boot time went somehow from 18 seconds to 10 seconds (Don't know if this is some how related or I just noticed now after a Windows update)

Quick Question for all: Does your onekey recovery button still work? I can't get into the BIOS anymore. Not sure if it's something with the button or the new BIOS disabling it somehow.

 

My ONEKEY Recovery button works fine after the BIOS update.
Did you perhaps delete the recovery partition when you installed Windows 8 beta ?


·

 

After further testing I'm still having the issue.

I'll send an email out to the team.

Sorry for the trouble.

 

Will Lenovo ever find a solution to this CPU Frequency locking problem ?

Or do they just not give a damn ???!!!

 

Okay, so it's been over a year since any activity on this thread.... any solution? I'm back on my old U300s after having to send my Yoga13 back to the depot for repair... still stuck at 44% frequency processor. Real bummer. It's a shame Lenovo doesn't push out updates like Dell and others.