cpu throttle ThinkPad T480 throttles to 200Mhz on all cores when plugged into power

Kiritaku · April 19, 2018

Sub Guys

I've had some real problems finding help for this one so I though I'd ask the best people.

Title pretty much says all. The following is a copy&past from my reddit post:

Specs:

i5-8250u
Nvidia Mx150
16GB DDR4
Samsung 981
Windows 10 Pro 64
All Updates and Drivers (Including Bios) installed (2018-04-18)
Temps very rarely hit above 80°C

My ThinkPad T480 goes as low as 200-400 Mhz when under a medium load (30%, or higher obviously) for a longer period of time(minutes or <10 minutes after reboot). This mostly happens when playing games but is somewhat reproducible with a synthetic load like stress tests.

I could observe the issue when playing League of Legends and CIV VI. To my knowledge the specs should be more than enough to run these at. At least my 6200u 940m(non X) 700€ Laptop could handle this load.

There is a slow drop to 1.4-1.8Ghz over time and then it suddenly drops to 200/400 Mhz. This is a Windows issue. It happens only when plugged in (Docking-station with 130 Watts or Original Plug with 65 Watts). If somebody has another idea or suggestion to what it could be I'd happily investigate.

It happens regardless of the Windows power-plan I chose. Even with the two additional ones Lenovo supplies via their software. There is an Windows Event-log entry with Code 37(Warning) basically saying it throttled my clock speeds. I have never observed this issue when playing unplugged, even for longer periods of up to 90 minutes.

Changing the power-plan setting with video playback to balanced as suggested in various forums does not help as well.

Addition: Intel Extreme Tuning Utilities says it's hitting a power limit somehow. The CPU will go down as low as 7 watts over "longer periods of time" like 20 minutes of load.

Is there any way to keep Windows from lowering the clock speeds below a certain threshold say the CPU base clock of 1.6Ghz?

If you need further details I'll gladly do everything I can.

nopethefuuuckout · May 1, 2018

This is damn near the same thing I'm experiencing as well, although my unit will quit throttling at about 1.5ghz (5 watts). I just checked and I have the windows events as you, 37. I *believe* this is an issue with gpu temps. I wrote pretty extensively about it on reddit if you want to see my findings.

did you ever end up solving the issue?

scr4bble · August 20, 2021

I managed to COMPLETELY solve the CPU throttling issue in T480 after few years fighting it - by using "FIVR Disable and Lock Turbo Power Limits" checkbox in ThrottleStop tool (in combination with "PROCHOT Offset = 10" && Lock PROCHOT Offset).
ThrottleStop link: https://www.techpowerup.com/download/techpowerup-throttlestop/
Now the laptop runs a full speed and only throttles when temperature reaches high levels (>90°).
The main culprit was power throttling (happened when temperatures were completely fine - e.g. under 65°C, laptop throttled CPUs here for whatever reasons that I never found). Throttling mostly happened when laptop was in a docking station - CPU was throttling also without docking station but never critically - with docking station it often got stucked at 799 or 399 MHz and never went back up.
My Laptop: Lenovo T480 i7-8550U MX150 Win10.
Credits go to unclewebb (ThrottleStop & RealTemp Author): https://www.techpowerup.com/forums/threads/cpu-being-throttled-while-temp-isnt-high.275814/