Hey, so I’ve had this problem for at least 1-2 years. When I haven’t launched Overwatch (1 or 2) since my computer starting up (in relation to when I restart my pc occasionally), Overwatch will eat up my CPU resources like crazy (100% cpu usage) for at least 2-3 minutes. After it’s done, it will no longer have this problem until I restart my PC and the game has not been launched yet.
Additionally, it is the only game that has this issue from my testing. As mentioned before, I have had this problem in Overwatch 1 as well, as early as 2 years ago.
First time I enter the game, the main menu is leeching off my CPU at 100%. While in practice mode, hugging and staring at the wall, constant stutters and my pc starts sounding like a jet engine within half a minute. FPS is high and “relatively” stable but I’m afraid to let it work any longer because it starts heating up.
Launching the game second time after force closing it, CPU utilization is now between 40-70% and stutters mostly disappear. As I leave it running for a while, it reaches 100% CPU again and frames start dropping very frequently. Progressively gets worse without anything happening on screen.
Sounds like shader cache behavior. When you install new Nvidia drivers the cache will need to be built the first time you launch the game. This will usually max out the processor for as long as it takes for it to finish. If you went into the Nvidia control panel and disabled the shader cache for whatever reason then this will happen every time you launch the game.
Finally, there was an Nvidia driver version earlier this year where the shader cache was completely broken with Overwatch and would rebuild it every launch even when it was enabled. The current 526.98 driver doesn’t have this problem on my system.
That much I can see as a reason it would be happening. Similar things happen to me in CoD (any of them) when the shaders are first being installed. When I played Warzone (1.0) for the first time, my CPU was being eaten away at because of “Shader Optimization”.