Long load times on old cpu

This is a really old issue but was never resolved...
I get long, and I mean long, loading times especially in groups.
Yet I know this is isolated to my pc, because everyone is halfway across the map before I see anything.

Sometimes in extreme cases, I have completed an entire map while the shaders are still loading and the two gears are spinning.

This issue is much less prevalent solo, act1... shader issue?