Benchmark performance for lower-end GPUs

[mokargas]

Area lights are expensive for low-end GPUs. Benchmark against lower spec Intels

[mokargas]

Looks like an improved shader is on the way https://github.com/mrdoob/three.js/blob/1558bf0ec01e5b16e26db26bba5495fa0e49f24d/src/renderers/shaders/ShaderChunk/lights_physical_pars_fragment.glsl