Question FPS drops in game, fixed by alt+tabbing


Aug 10, 2017
Hello! Thank you in advance for any assistance rendered with the below issue. I am having strange FPS drop issues (details below) and really trying to figure it out ...

Computer Specs:
MOBO: Asus Rog Strix H370-F​
CPU: Intel Core i5-8400​
GPU: Nvidia GeForce GTX 1070 8G Dual OC​
RAM: 2 x 8 GB (Dual Channel)​
PSU: EVGA 650W 80+ Gold Certified​
Dual Monitors - HD 1600x900 Resolution which I use at 1080​
Windows 10 V.20H2​
Will use League of Legends as an example-
Regularly or normally, I have 200+ FPS in game, and when I alt+tab, it will obviously (and expectedly) drop to around 16-17 FPS because the game is in the background. Sometimes, when I return to my monitor that has League, the FPS wont go above 60 until I alt+tab a few more times (back out then back in) to the game, then my FPS will go back to what it usually is. While 60 FPS is fine, I can clearly feel the difference when it happens, and it becomes a little laggy. It does not recover on its own. I will need to switch windows for the FPS to go back to normal.

For the record, I play league in Windowed Borderless - and I haven't changed anything in the game, nor my resolution. If this was a constant FPS drop, I could probably pinpoint it to my RAM or something, but my memory is at 60% usage, CPU at 50-70%, and majority of it is taken up by my browser (Opera GX) which isn't the culprit that I alt+tab to (Discord usually is..)

  • I have closed everything but1 software in the background but it still happens (tried different software to see if maybe that was the issue)
  • Checked the CPU/GPU temps to make sure they were normal (they are).
  • League isn't the only game it happens in, so I haven't tried reinstalling
  • Updated drivers (tried reinstalling)
  • Windows is up to date
  • Nvidia Settings - set to Maximum Performance / not Power Saving Mode
I appreciate any help that you guys can offer with your amazing wisdom.