The easy part of the answer is to say yes, there is a difference. You will always run faster in a competition when you’ve got a bit of adrenaline and nervous energy helping you along. And you never really run 100% in training even if you think you are, maybe 98-99%, but never 100% until you have a guy right next to you about to snatch a medal position from you.
The hard part is saying how much, everyone is different. How much effort you put in during training, and how much race day psychology will speed you up differs from person to person.