GPU OVERCLOCKING, what to expect?

I have ULTARBOOK UX32VD, so it has NVIDIA GT620M. At this moment am using it for gaming. few weeks a go I tried to overclock it's GPU(I know it does sounds crazy, stupid, and insane, but but it worked) but I do not see any difference in frame rate during gaming 


naturally GT620M in my system is clocked at

Core clock 625MHz

Shader clock 1250MHz

Memory clock 900MHz 

 

I successfully overclocked it

Core clock 800MHz

Shader clock 1600MHz

Memory clock 1050MHz  


so my question is whit this much of overclock approximately by how much improvement should i see?

Realistically speaking it's not going to make your computer gain more than a few fps in most games. You have to also realize that with that overclock you are now making a lot more heat which isn't doing your laptop any favors. If you can't perceive much of a difference, that's about what I would expect. My advice would be to keep your GPU at stock speeds and reduce the wear on your components. 

EDIT: It's not that overclocking doesn't ever yield big increases in performance, I'm just not sure it is worth it in a laptop where you have limited cooling.

Performance from overclocking the GPU core could scale perfectly if you are not CPU bound and have enough VRAM. But there are far more factors that inhibit an increase in FPS, such as VSync.

175/625=0.28

28% increase in FPS.

I was so interested how much improvement i would achieve, so I overclocked it even more, and run Unigine Valley Benchmark.

If you are interested here are the results.
I set benchmark on the lowest settings to see max difference.
Render: Direct3D9

Mode: 640x400 fullscreen

Preset: Custom

Quality: Low

 

So the stack

Core clock: 625MHz

Shader clock: 1250MHz

Memory clock: 900MHz


Achieved

FPS: 40.9

Score: 1712

Min FPS: 17.1

Max FPS: 73.1

Overclocked to max

Core clock: 1000MHz

Shader clock: 2000MHz

Memory clock:1080MHz

 

Achieved

FPS: 42.7

Score: 1787

Min FPS: 13.4

Max FPS: 77.9

 

and I did another run on same overclock settings, but know I literally froze this ultrabook(by spraing it turned upsidedown "dust remover spray")

FPS: 43.7

Score: 1830

Min FPS: 19.4

Max FPS: 78.8

Im not experience with the gains that should be seen but either your card isent getting good gains or mine is really getting good gains. I overclocked my 280x from 1070 to 1150 on the core clock, touched nothing else and was able to see a 4 FPS improvement on valley.

good job on the overclock. i duno if it's worth the extra heat.