Windows 7 - overclock

i have a geforce 880GTX graphics card i overclocked the core clock from
592 mhz to 632mhz
memory clock 921mhz to 1053 mhz i am wanting to know how can i know if
overclocking it to this is ok is there any signs that tell
you you've overclocked too much

There are two major things to look out for when over clocking:

BSODs and major heating up of the your GPU/CPU.

BSODs are easy to spot (obviously) but if you are looking to measure your CPU/GPU temperature have a look at Core Temp (Core Temp ).

Oli

would you recomend and settings that are safe enought

my GPu went up 2 celius a

which setting improves videos playing them how much would you recommend the settings to

2 degrees Celsius is fine; as long as your CPU/GPU doesn't break its maximum temperature it'll be fine.
Its maximum temperature threshold is probably 100 degrees Celsius.
Overclocking your GPU would improve video playback but by the look of your PC's specs I would say you wouldn't notice a difference anyway.

The settings you are currently using seam to be fine, as long as you don't go overboard you shouldn't have too many problems.

Oli