Whats a Good fan speed for xfx 9600gso?

[shohag2018]

i have my gpu fan spinning @ 45% currently...@ idle its 67-68 degrees...(its very hot here in my country 41-42 degrees).
problem is when i try playing devil may cry 4 it jumps upto 90 deg after a while and the game crashes.

im not the best at hardware monitoring, so im confused ..does setting speed further higher cause damage to the gpu or mobo? does it require more watts of power? i have a thermaltake 420w psu now..
if its safe to increase my fan speed, what speed should i set it to?thanks in advance u guys rule..

 

[evongugg]

Clean the dust. Reapply thermal paste.
Regulate the fan with Rivatuner.
It is safe to increase the fan speed. You don't need extra power.

 

[evongugg]

You can run the fan at 100% all of the time.

 

[shohag2018]

thanks for ur reply guys..thanks a lot.