(TL; DR is at the end of the post)
My current laptop is an HP 15-r218nv. I know this isn't the best laptop for games, but it does the job. I bought it 3 years ago and it worked great all the time. The laptop started to overheat last year, and because I didn't have the money to clean it, and I wasn't sure enough to open it and clean it myself, I took out the battery, the easiest and most efficient way to do this Do reduce the heat and don't lose much power. I continued to play games as usual, and about 4 months ago there was a storm and the storm roasted the power stone. I was recently given another laptop and the charger for this new laptop could fit in my old one and charge it. So I decided to reset the old one to factory settings and update it to Windows 10 version 1903 (I had Windows 10 version 14XX).
Since I have a charger, I have to reconnect the battery of the old laptop. I did that and downloaded some games again. I started playing games and I noticed something strange playing CS: GO. I played CS: GO without charging the laptop and I had great frames per second, around 100 frames per second. The battery had a low percentage and I plugged the charger into the laptop and immediately noticed a drop in fps to 20 fps and a decrease in CPU and GPU usage from ~ 80% to ~ 35% and ~ 100% to ~ 50 %.
I thought the drop in FPS was due to the laptop changing some options and settings due to the battery / power plan. So I waited a few seconds, but the FPS didn't bounce back. When I noticed that the fps would not jump up again, I pulled the power plug out of the socket to do a test and see what the fps would look like. My fps jumped straight back to 100 fps. The next day I decided to run CS: GO again and again noticed low fps. I tried a method other than the problem to see if it would solve the problem.
My laptop has an Intel Core i7-5500U and an Nvidia GeForce 820M. I use the integrated graphics as it is more responsive and faster than the Nvidia GPU.
In the NVIDIA Control Panel, I can choose which GPU to use for each program, and I thought I forgot to switch the preferred GPU for CS: GO to the integrated graphics, but that wasn't the case. I thought the control panel was faulty, so I disabled the Nvidia GPU through Device Manager. The game was still sluggish.
I reactivated the Nvidia GPU and searched for answers to my problem on Google. The alleged solutions I found were:
It may be a BIOS setting. This could be the reason, and I might say because I can't see a setting that would cause this, but my BIOS has a very limited number of settings that I can change.
A power / battery plan option is faulty, which is not the case
Maybe I configured things wrong in the control panel of the Intel iGPU, which is not the case either
Neither of these solutions worked, and I have no idea what to do next. If anyone has any idea what the problem might be, I would appreciate it if you could help me
The CPU and GPU utilization of my laptop drops considerably when it is connected and is almost halved. Changing the BIOS does not help, the energy / battery plan is configured correctly and the configuration on the graphics control panel is set correctly. I don't know what to do next.