Opening multiple instances of a game in Sandboxie causes "System" to report high GPU usage in TSKMGR

Hi, I play Runescape a lot and I've opened 16 windows of the game without Sandboxie. I don't know how to open more native instances of RS, so I turned to Sandboxie. I now have 16 windows using the regular RS client and SB allows me to open up another 7. My task manager shows all instances and they aren't using much resources individually. The problem is that the "System" selection spikes to around 80%+ of GPU usage when I get all the games logged in and running. When I just have the first 16, everything runs pretty smoothly but when I add the other 7, it's jacking up to 80% GPU. Is there a solution to lowering the GPU usage? Or is there another workaround? Any help would be appreciated, thank you.

 

Why do you want to play this in Sandboxie? If it's a trusted app or game, my advice is to run it on your real system. No need to sandbox every app or game, Sandboxie is mostly meant as a browsing protection tool.