Looks like it. I was curious today and did some testing looking at my CPU usage and GPU. Apparently, without self shadowing turned on, my GPU (Radeon 6870) only uses 11-15%. When I turn it on and set it at 8192 resolution, I get a jump to 50-60% usage. I still have 60 FPS at this point with bump map terrain, bump map self, detailed terrain/water, reflections and detail slider at max.
The following are turned on in addition with these: bump map terrain, bump map self, detailed terrain/water, reflections and detail slider at max.
Turning on the environmental slider to full only drops my FPS to the 20-30 range.
Turning on Shadows on Others only drops it to 30-40 FPS.
Turning on bump map buildings only, it stays at 60 FPS.
Turning on bump map others only drops it to 40-50 FPS.
This was done at a rather busy airfield in the tower, in F5 mode. About 15-20 players within icon range. Probably a few more beyond that.
Turning everything on drops my FPS to the 10-15 range. Unplayable.
However, during this entire time, my GPU usage never exceeded 70%. My CPU however was nearing max load, a Quad Core Q9550 @ 2.83Ghz.
I keep shadows at 4096 res and turn on smooth shadows, along with bump map terrain, bump map self, detailed terrain/water, reflections and detail slider at max. These settings keep my FPS at 60 even in 30+ players environment. Turning on 8192 shadows cause my FPS to dip to the low 40s in 30+ players areas. But a steady 60FPS otherwise.
With 4096 res shadows/smooth shadows, my GPU usage is only 30%.
So the point of this thread is to ask how come AH is so CPU dependent? Wouldn't it be better to even the workload of the CPU and GPU so that players may achieve higher FPS if they have a low/med-end CPU? Why only make self shadows use the GPU?