But isnt the 500 watt power supply enough?
Yes and no. For a lot of video entry level gaming cards, 500watts is enough.
But, power supplies have different build qualities. The capacitors degrade eventually in even the best of brands with 10 year warranties. This means your total power output will eventually decrease and the quality of the power will decrease leading to random computer failure when its under load.
I dont know the brand or age of your power supply, so as a safety measure i recommend replacement.
My recommendations from cheapest kia to mercedes are
Corsair cx550
Corsair cx550m (modular plugs)
Seasonic plus gold 550
Corsair rm550x
Seasonic prime
They are all acceptable in my book. There are other good brands. But these are my goto brands based on personal experience, warranty, and reviews.
They are all quality units in my book. They tend to produce good to excellent quality output and have quality internals. That means it should last a while if it arrives working. However even the best of models have a stinker every once in a while that are dead on arrival.
There have been reports of fan failure (noise) on the seasonics when new. But I havent encountered this yet and ive bought 4.
There have also been reports if failure of the extremely high wattage (1000+ watt) RM series from corsair. But this was from several years ago. So corsair might have isolated the issue since then.