Has anyone else ever noticed this? I've seen it on more than one of my 3dfx cards over the years, just never thought much of it.

https://drive.google.com/open?id=0B6vqgf6MYPD1YTFSLTZKVmlOZlk - Google drive link


I've tried tweaking driver settings but nothing seems to stop it. This can happen on any map, on floors or ceilings. Anyone else noticed this before?