I clicked on "find optimal" which bumped 3D clock and memory clock up nicely but i just wanted to put it slightly higher and to a nice round figure, but when i do it says please use test to check etc, so thats what i do and it comes up with a box saying this test will take several seconds blah blah blah and i click on "ok" and it just reverts back to the optimal settings? why is it? is it because its on the highest safest settings and any higher could damage my gpu?