Beware of the Accelerator While Speaking
There seems to be a general misconception that speaking fast makes you a good speaker. While you might be able to impress people who are not proficient in a language by speaking fast,your efforts will surely fall flat while addressing speakers of that language. Besides making your speech difficult to follow, speaking fast might also lead you to making mistakes. You are not giving yourself enough time to organize your thoughts and at the end of your speech you might realize that you have missed important points and have not managed to convince your audience. One of the keys to effective speaking is to deliver your message loud and clear and to ensure that this happens, you need to maintain an even pace which is neither very fast, nor too slow.
In addition to your message not getting conveyed owing to you talking too fast, this video brings out another negative aspect of express pace. Keep in mind that you stand a much better chance of impressing your audience by showing them how WELL you speak English rather than how FAST.