I bought a Lenovo Y520 a few weeks ago. It's got an Intel i5-7300, a Radeon RX 560 4GB, 8GB RAM, with Windows 10 Home.
When I got it, it had some issues. I noticed it was pretty slow for a brand new computer with a good CPU. It's blue screen 3 times in the three weeks I have had it. I installed a few games, Warframe, PUBG, Witcher 2 Enhanced, System Shock Enhanced, HITMAN, and Quake 2. On the more demanding games, I was able to get between 60 and 100 frames. On these same games I now get under 30, and sometimes they can't even reach 10 frames. Other times they run just fine. A week ago I played Warframe for an hour and got the usual 60 to 100, turned it off and came back to it two or three hours later and it couldn't reach 10 frames. The computer hasn't ever been dropped or damaged. When I ran a program to check temperatures, all were normal. The CPU usage seemed really high though. So maybe the CPU is bottlenecking or something?
I went to r/techsupport and was told it could be Windows updates. The person suggested I do factory reset, so I did. Then I shut off Windows Updates, but it didn't help. I went to TomsHardware, but got no help there.
Could it be possible that, for some reason, my computer is switching between the GPU and the motherboard's onboard graphics?
Any ideas are greatly appreciated.