Question FPS drop after 15 min. ingame on laptop

May 7, 2020
Hey Guys
When ever I play games on my Thinkpad 580E, I get these sudden fps drops while in game. The game would run smooth at 50 fps, for the first 5-15 minutes, but the fps suddenly drops to about 15. I have noticed that CPU usage drops from about 60% to 20% as the fps drop occurs. Before the fps drop, my GPU would be at about 80% usage with spikes of 95%, after the fps drop my GPU runs at full capacity at about 95%. I have included a screenshot of my task manager so you can see what happens as the fps drops: View:

I have had this issue in a lot of games including: Red dead redemption2, Fall out 4, Far cry 5, Cities skyline and Subnautica (Where the task manager screenshot was taken)

So far I have tried following solutions:
-Set everything to max performance in windows power manager
-Setting minimum processor state to 100%
-Disabling the intel power manager in BIOS
-Installed fan software so the fan runs at 100% (Temp doesn’t seem to change when the fps drop happens)
-Upgraded my ram from 8GB to 32GB (a bit overkill but it was cheap)
-Attempted fixes and how to’s on optimizing the individual games
-Updated GPU and CPU drivers

So far none of the above has made a change in the fps drop, and I have now run out of forum posts to read.

My system:
CPU: Intel core i7-8550U
GPU: AMD radeon RX550 (Horrible GPU btw. But that’s another discussion)
RAM: 2x 16 GB Crucial DDR4
HD: Samsung 1TB SSD

I know my system isn’t a high-end gaming laptop, but it runs solidworks simulations like a champ, and these simulations often require quite a bit of CPU, GPU and RAM. And I don’t get why it would run a game fine for the first 15 minutes if it’s a hardware issue. Any ideas on what I could try?
May 7, 2020
It turns out to be a heat problem with the Lenovo E480, E490, E580 and E590. When the laptop reach a temp of about 75 deg. it starts thermal throttling like you would expect, but when you have a lot of cpu usage the temp. keep rising. When both the fan and thermal throttling fails to keep the temp low, the cpu just restricts the usage to 40% to keep it cool.

As a solution i have tried changing the thermal paste, which turned out to be fairly easy and cheep. I have also bought a stand with a build in fan, for the laptop to sit on. This lowered my awerage temp. about 10 deg. which is enough to awoid the fps drops in some games. However it is still happening in heavy games like Subnautica and Far cry 5.

There is an entire thread discussion the issue with lenovo here: (Lenovo has given up on a solution)