Limit Editor maximum CPU usage

Hi, I'm trying to bake a scene.

I started with 4 texel resolution and was able to get through the baking process. However the resulting scene looked blotchy and not at all naturally lit.

I upped the texel resolution to 50, increased the rays from 1024 to 2048, and just in case upped the lightmap size from 1024 to 2048.

Basically what happened was my CPU was at 100% for hours. I left it to bake and in the morning I found out it had crashed. So I tried again, this time going to my power settings and limiting the CPU max state to 90%. Same thing.

So I'm wondering if it is because Unity will take ALL of the CPU to bake that it crashes. Maybe if I could adjust a setting in the editor to limit the max processor use, because setting the priority lower doesn't seem to change this. I wouldn't mind waiting longer if it would keep from crashing...

Anyone else have some lightmapping experience? There is really a lot of debate as to what GI settings are standard for low, medium, high lightmap quality.