I'm using my Toshiba C650 laptop with an Intel Core i3 2.53 GHZ and an 4GB Ram that i using for video editing,gaming and social networking but awhile i'm rendering my video in Vegas Pro my CPU usage kicks to 100%. Does this may harm my computer specially if the rendering takes an couple of time and the CPU Usage stays almost on 100% for 15-30 Minutes... ??
Are the temps OK? I would say over time it could have a wear and tear impacted on the laptop components, rendering is a hard task for computers in general. Its like having a car and driving at full speed all the time, it will have a effect on the car and engine over time.
Agree with Britec, i7 cpu's are better suited for rendering however as long as you realize why your i3 is at 100% then you know that you are pushing that laptop as hard as you can. You may or may not shorten the life of that laptop.