safe? Depends on your GPU. Overclocking, in layman's terms, is to go beyond the performance of regular use. I wouldn't recommend it if you don't know how it works, because I tried overclocking an old GPU of mine recently and almost messed it up. I would only recommend it if you have a card with VERY nice cooling, such as EVGA's ACX 2.0, or if you installed liquid cooling onto the card.