Memory management is a serious business, in modern computing the costs of using memory is a bit biased from the user by utilizing the wasteful clock cycles on other operations. Performance related issues regarding memory can root to two common problems. First problem is cost of allocation. Often default supplied allocators like the one found in STL rely on the default implementation of malloc which doesn't always have optimal performance due thread-safety. Another problem is fragmentation, frequently allocating/deallocating causes holes of 'unusable' memory.