No performance loss at all. Max shaders at 60 FPS.
Either this is a real thing (which I'm beginning to doubt), or you're being pretty deceptive in leading people to believe that this is real with that statement.
Also
CPU: AMD Phenom II @ 3.4 GHz
RAM: 24 GB
OS: Windows 7 64bit
GPU: GTX 560 Ti @ 900MHz
My computer may be slightly above average but it won't make much of a performance loss on any system.
Then what is average?? Of everyone I know irl, only one person has ever told me that he has (actually that he's
going to have) a computer with 8+ ram. I think your community just has above average wealth/interest in computers