speed strip will only work on unlocked processors. if your's is locked then it will not do anything for you. Actually all it does is allow a chip that has a default multiplier of more than x12.5 to work in the lower multiplier range (x5-x12.5), it doesn't make your chip faster, or any difference if your chip is already in the low range.
People don't usually get those, as you can get the same effect by inserting a small wire into your socket, which costs nothing.