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ardimo
Paper Tape
Posts: 6
Registered: ‎01-10-2019
Location: DE
Views: 1,052
Message 1 of 16

Extreme throttling problem and i just cant find the cause

I got a t480 and a Ultra Docking Station at work and i have a really really weired problem and i am struggling to find a solution.

 

My t480 (u8550 Processor) starts throttling after sitting ~ 10-15 minutes in the dock without any logic reason. Some facts i have to get a more precise picture of the problem:

  • Outside the dock and connected to the USB-C Charger including with the Laptop everything is fine, even for hours of Work. No Problems there, everything is fine and i get decent Cinebench scores everytime.

  • As soon as i put the Laptop in the dock everything is fine for about 10 Minutes. Then the throttling kicks in and the Processor looses more and more Power until the clock stays around 800mhz.

  • It doesnt matter in which energy mode of windows I am (high power, optimized, energy save).

  • If i switch on/off intelligent cooling in the Thinkpad Vantage software the cpu goes up to 1,5 ghz for about 2 or 5 minutes and then starts throttling again.

  • Also i switched of the automatic airplane mode
  • Uninstalling Vantage has no effect. (Horrible Software by the way ... It starts slower than my whole development IDE including scanning the whole Project ...)

  • Everything (Software, Drivers, Bios, Dock Firmware) is updatet to the newest version available through Vantage (Did an update again just yesterday)

  • The Laptop is connected to the 64W Power Supply that came with the Unit outside the Dock, the Dock itself is connected to the 135W Power Supply that came with the Dock.
  • The Fan is spinning allways, even if the Processor is throttled and at around 55 C. If the unit is not docked it will be much more quiet - sometimes totally silent even.

I installed Intel Extreme Tuning Utility to find out the cause.

  • Its not about thermals! Temps are just fine around 50 - 65 C. Thermal Throttling does never kick in.

  • Its also not because of the Nvidia Card - I dont use it and it is allways cool. Ive read that some people had Problems with thermal throttling of the cpu because the gpu runs hot - but thats not the case on my machine.

  • What i can see is, that as soon as the throttling Problems begin "Power Limit Throttling" is either allways on or is most of the time. The Package TDP is then allways around 5 - 8 watts. Outside the dock its about 22 - 30 watts on load.

I have a workmate who got the same setup. We have both the standard Windows 10 Pro Version that came with the machine. I suspected my Dock to be the problem, so we swapped the Docke yesterday. I got throttling with his dock but he had no problem with mine ... I also pulled the power plug from my dock to reset it (dont know if this is a thing, but this was one suggestions i found on the net) but that also didnt help.

If i put the running laptop out of the dock the processor starts acting normal after 1-2 minutes.

 

Some explaination to the attached screenshot:

 

CRONO-T480_2019-01-09_003.png

 

The first 30 Minutes today everything was fine. Laptop was sitting in the dock, i was working and happy that it didnt throttle. I was updating thunderbold firmware yesterday and uninstalled Thinkpad Vantage and everything looked fine!

Then the throttling kicked in. The blue spikes show the power limit throttling kickin in every few seconds forcing the core clock down. Later its just allways on.

On the right side there is a spike in cpu clock for about 2 minutes, thats where i toggled the intelligent cooling in vantage (i installed it after throttling kicked in again to check if this "trick" still works.) but right after the clock comes down gradually again.

 

I just have not the slightest idea anymore what to do ... There are only two options left for me to investigate:

  • Trying a clear, non Lenovo Windows Installation - for this i need to wait for this or the next weekend as i have to work with this machine right now ...

  • Swapping the SSD with my workmate and check if the behaviour is dependand on the machine or the windows installation.

ardimo
Paper Tape
Posts: 6
Registered: ‎01-10-2019
Location: DE
Views: 985
Message 2 of 16

Re: Extreme throttling problem and i just cant find the cause

I Did a clean Windows install and let Windows handle driver installation. Everything went perfectly fine and i installed no additional Lenovo Software after that. But unfortunately no luck - 10min after it went into the dock it started throttling again.

 

DESKTOP-R940QTI_2019-01-21_Image-002.png

 

 Seems like I have to assume some hardware defect ...

 

Edit: Tried a different Power-Suppyl, but also no luck.

Edit2: Got the opportunity to try one of the smaller docks (USB C Dock), but i ran into the exact same problem again. Besides that this Dock (or the connection on my thinkpad with just one USB C for this Dock) was not able to drive 2 1440p Displays ...

scr4bble
Fanfold Paper
Posts: 8
Registered: ‎09-04-2018
Location: CZ
Views: 487
Message 3 of 16

Re: Extreme throttling problem and i just cant find the cause

Hey, did you manage to solve the problem? I am facing the same issue and I am already frustrated...

 

Community SeniorMod
Community SeniorMod
Posts: 10,071
Registered: ‎01-01-2010
Location: US
Views: 472
Message 4 of 16

Re: Extreme throttling problem and i just cant find the cause

Do you have the latest BIOS?


Rich


I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

If a response answers your question, please mark it as the accepted solution.

I am not an employee or agent of Lenovo.
ardimo
Paper Tape
Posts: 6
Registered: ‎01-10-2019
Location: DE
Views: 444
Message 5 of 16

Re: Extreme throttling problem and i just cant find the cause

I have found a bit of a weired solution: Cooling the dock actively helps. I got that tipp from the german Thinkpad-Forum.

attachment.jpg

This self-made USB powered radial fan (That type you can find on Desktop GPUs) blows right on the dock connector, under the latop and in between the screen/keyboard when closed. Not throttling at all when cooling this area. One or two minutes after removing the fan the laptop starts throtting again. I now have to make another fan and let it run slower and more quiet. (as this is my pocket fan intendet to keep me cool in the summer and not my thinkpad ...)

 

I have 5 older Thinkpads at home, including Docks (the newest is a t440p) and none of them are so anoying in combination with the dock.

 

At the moment i have also the problem, that the dock wont recognize my usb ports ... pretty nice considering that this is one of its main features. At last it still powers my two screens ...

scr4bble
Fanfold Paper
Posts: 8
Registered: ‎09-04-2018
Location: CZ
Views: 428
Message 6 of 16

Re: Extreme throttling problem and i just cant find the cause

@richk yes, I should have the latest BIOS.

"No upgrades for 20L5000BMC System Firmware, current is 0.1.25"
scr4bble
Fanfold Paper
Posts: 8
Registered: ‎09-04-2018
Location: CZ
Views: 423
Message 7 of 16

Re: Extreme throttling problem and i just cant find the cause

erik_h
Punch Card
Posts: 127
Registered: ‎01-15-2010
Location: US
Views: 412
Message 8 of 16

Re: Extreme throttling problem and i just cant find the cause

first, I know this sounds like a dumb question, but are you sure that the dock you are using supports the max power load of the laptop?  If I recall correctly, some of the Lenovo docks do not play perfectly well w/ all of the Lenovo laptops, so you can theoretically draw power down even while plugged in.  a power loss might be the solution.

 

Also if you are getting extreme heat near dock connector that is probably a bad connection.  Any bad connection will reduce contact area.  that will reduce the apparent cross section of the circuit and will raise resistance and make heat in that location. if so, cooling is a stopgap solution, which would not fix the real problem I think.  I would try to see if problem replicates with different dock / same laptop, and different laptop / same dock.

 

 

ardimo
Paper Tape
Posts: 6
Registered: ‎01-10-2019
Location: DE
Views: 377
Message 9 of 16

Re: Extreme throttling problem and i just cant find the cause

No, the Docking station is made for this Laptop. The Charger that came with the Docking Station is also way more capable than the one that came with the laptop (135 W vs 65 W).

 

I already cleaned the connectors and checked if something is getting hot - no it does not. I dont know if the Problem is the dock or the laptop and what is causing the throttling.

 

All i know that i am pretty frustrated with "modern" Thinpads by now. If i would have paid with my own money for it i would be really angry. I am really tempted to replace it by an older Thinkpad like an t440p ...

scr4bble
Fanfold Paper
Posts: 8
Registered: ‎09-04-2018
Location: CZ
Views: 368
Message 10 of 16

Re: Extreme throttling problem and i just cant find the cause

@ardimo I have the same feeling. I paid the laptop myself and I really didn't expect such problems. Laptop for 2k and performance like 10years old computer when it starts throttling... Lenovo f*cked this up pretty bad.
One year after buying and still no update that would fix it.

@erik_h - the docking station has better power supply than the standalone charger for laptop. Also it's from Lenovo exactly for this model I think - it was also pretty expensive comparing to the other docking stations for just a slightly older models...

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