If anyone is interested, no matter what Board you use the performance is dramatically reduced as soon as you rotate the screen. This is a measurement of PI3:

I executed glxgears without vsync. measurements are average of fps

0_1535224120015_Screenshot 2018-08-25 at 21.08.03.png

So without rotation the performance on the pi3 is a lot better. On the Tinkerboard it is even worse as it only supports Open GL ES and I have not found a solution to get that running with Electron.