Hi, the card can draw a good 360 watts. So unless you have installed an old or power-hungry CPU or connected a lot of other components, the 750 watts should be enough without any problems.

For example, I also run it with 850 watts and there are said to be people who even run this card with less than 700 watts.

As long as it's a decent power supply and you don't have any problems, you can leave it in. If you are unsure, you can always upgrade. Power supplies aren't that expensive now, even with good brands, and they last forever. So you'll be on the safe side in the future.