I dont know if this is interesting to anyone, but I write this any way.
I broke my "new" MOBO again, and have to temporary use a 5 year old MOBO with 1.4GHz Athlon and 512MB 133 RAM.
So the PC is exactly the same exept for the memory and CPU.
AMD Athlon 2800XP -> AMD Athlon 1.4GHz
512 MB "400 MHz" RAM -> 512 MB "133 MHz" RAM
The video card is GF FX 9500 ultra with 256MB.
I use 128 size textures.
Framerates went down to ~25FPS from ~60FPS
The worst times in the game, frames drop below 10 FPS.
I thought the video card had a bigger roll.
Now I am going to test, if I get the same frame rates with an older GeForce card. GF 4200Ti with 256MB.
Back to the 90's