Leave it locked then. It is the luck of the draw. They are locked because they fail the grade to be utilised as a different spec CPU but the rumour was that due to demand some chips destined to be "better" cpus got utilised at the lower end.
Have you monitored your CPU usage during gaming? Does it struggle? Yeah I have the 4th core unlocked but it has never been a source of a bottleneck and I would have though that with the normal 3 it should cope okay.
Having said that if you can upgrade then why not ( unless you are skint
). I suggested an SSD upgrade but that does not have that much of an impact during gaming. OK folks do not flood me with evidence to the contrary. In my experience of my hybrid drive the difference between a standard HDD and the hybrid is markedly less significant during gaming when compared to say boot times and intense read/ write situations.