Difference between low and high Shader Details ?

[Sashq]

Hi,
i don`t see any difference between the low and high Shader Details, but the FPS increase is really great. Has anybody a good compare Screenshot where you can see the difference ?

Greetings Sash.

 

[dreten707]

i think it has somethin to do with reflection and bumpmapping
dont no actualy everythin is high with me

 

[logic1422]

Shader Detail: This option can either be set to Low or High, and controls the level of the special effects drawn by "shaders", which are complex graphics functions supported by your graphics card's hardware. The performance difference between Low and High is quite noticeable, however the image quality difference is almost totally unnoticeable, so I would recommend Low for those looking for more FPS with no real drop in image quality.

source: tweakguides.com

After reading that, I went back a attempted to take screenshots with the shader on low and on high. After I had taken the screenshots, I noticed that three had been no change in FPS OR image quality which leads me to believe that nothing had been changed.

After looking a little closer, something that I have missed or never really payed attention to caught my eye:

Game started
Initializing renderer...
Error: Material "engine/occlusionproxy" uses unknown shader "Occlusion"​

I know that I have r_occlusion "1" so what could be causing this? Does this even affect the shader model? Occlusion culling detects hidden objects and prevents them from being rendered is what I discovered after a quick google search. I have DX 7 enabled and my video card is a GF4 MX 420.

EDIT:
After doing some reseach about my video card (which is a card you can get at a garage sale for about 2 dollars), I discovered that I have Z-occlusion culling on the card.