I'd thought I'd covered that in the part where i said "25% of the transistors only get used 5%". If a transistor is critically import for the *functionality of the GPU then it's used every time the GPU is used because without that the GPU wouldn't function.Odd question, of course depends on the functional value of the 25% of transistors. Most transistors have a very small activation time but are critically import for the functionality of the GPU.
*Not sure what you're classing as functionality because that's a pretty wide remit.