Webgl Rendering Much Slower on Desktop than Mac Pro

I’m working on an n-body simulation and drawing hundreds of small spheres to the screen. On my mac pro I can draw about a thousand smoothly but on my desktop with a gtx 1080 it very jittery (~5fps). Anyone know how I can diagnose/fix this issue?

I think it might be having an issue with deciding between the built-in intel graphics vs the graphics card. The issue occurs on both chrome and firefox on desktop.