Ok, that helps. How to speed up video encoding: how to speed up video encoding - Google Search
To summarize the results: video encoding speed almost entirely depends on your CPU. "Core i3 M 370"? That's a laptop. So, no replacement upgrade CPU and no overclocking. You could add 2GB more RAM if the laptop has room for more RAM, but the improvements will be more for the system overall, not for video encoding specifically.
Sorry to say, there is not much you can do to improve your video encoding speed with your current system.