You won't normally see any difference between them for normal tasks such as web browsing, and music/video playback. Only heavy stuff such as encoding etc should be around 40% faster.
Your CPU is NOT damaged. A CPU works like a switch, either it works, or it doesn't. There is no such thing as a half working CPU.
Your temperatures are also completely normal. When the CPU is idle, it will reduce its clock speed and voltage, so it draws much less power, and stays at a cool 30C. However, under full load, it will draw more power and heat up, but anything under 70C is perfectly fine. Your CPU will only get damaged at 100C or higher. But before that happens, today's CPU's will shut themselves down to prevent any damage.