game performance becomes slow/jerky

i have an hp dv5 1006ax laptop with windows 7.
my problem is, the game performance becomes slow/jerky (not smooth) when power is unplugged. i tried changing my power plans. but no use.
when it is plugged in it works smooth.
i have ATI Radeon HD 3400 on it

please help

can u be more specific about the power plan changes you made? for instance, did you change the on battery settings to be the same as plugged in?

i changed it to best performance and reduced the contrast..
is that what you meant. or else can you be specific

sure, have you tried changing this setting to 100%

No i didnt try... Thanks

did that fix it?

no sir.. Any thing else

it runs absolutely smooth when plugged in

but its terrible when unplugged


please help

maybe there is a bios setting that changes the cpu speed when on batteries that overrides windows settings?

yes but its not there on my laptop


please help somehow