I am an individual contributor in the team working from off-shore. My manager is onsite and he assigns work to be on calls. The project is in very initial stage so I am mostly doing POC's. However, I get this feeling that I am bit slower in completing the tasks than expected. It takes me longer to resolve issues though I donot take many breaks during the day. Please explain how do I know if I am going with right pace or what can I do to complete things faster.
I've found that almost everybody in the world likes to be asked their opinion - and I'm sure your team and the person you report to would appreciate your being open with them and asking what they think. I've spent years of my career being afraid of what I thought someone might have been thinking - and pretty much every time I actually asked there was no problem and I felt happier.
Now I'm very comfortable doing it and almost never have any stress around job performance as at least I know when someone thinks I'm not performing as well as they think I should - and we can discuss and improve.
It sounds like you're afraid that you're performing under the minimum base-line. The best way to find the answer to this is to ask your boss for feedback about your performance. Keep it professional and non-apologetic. If there is a problem, take it to heart and try to fix it.
As far as evaluating your personal performance, start measuring. The next time you start a task, note the time, expected difficulty, and estimated time of completion. When you finish note the time, actual difficulty, and actual time of completion.
This gives you a starting point to measure your performance.
Hope that helps.