If a std::vector is causing performance problems there is some major disconnect between how it is being used and how it is meant to be used. Someone else noted

If a std::vector is causing performance problems there is some major disconnect between how it is being used and how it is meant to be used. Someone else noted that debug more will stifle performance, which is true and the most likely culprit. Other problems can include constant resizing and memory allocation and copying, but when something is 1/100th the speed it should be, that screams debug mode being left on, which will do bounds checking on every access.