Minimum Recommended System Power (W), 500 W
What's the (max output) wattage capacity of your power supply ?
It's printed on the label on the power supply.
xxxx WATTS .
If that's more than 50 watts below 500, you are probably overloading the power supply all the time the card is installed, or at least when you play a recent high end game which places more load on the video chipset / system, and the power supply will fail eventually..
Your power supply must have at least the minimum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD ! )
If that info is not in the ad for the video card, you can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements. Some power supplies have two or more +12v ratings - in that case, add those ratings to determine the total +12v current capacity.
If you're a gamer...
In most if not all cases, the max capacity rating of the PS is an intermittent rating. It's recommended that you do not load your PS to any more that 80% of that rating if you are going to be using something that puts a constant load on it, such as playing a recent game for hours on end. In that case, you multiply the min capacity stated for the system with the particular video chipset on the card by 1.25 to find the min. capacity of the PS you should have.
If you need to get a PS with more capacity, you can usually replace it with any decent quality standard sized standard ATX PS.
Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.
Don't buy an el-cheapo (in quality) PS.
See response 3 in this:
I no longer recommend Cooler Master, AOpen, or Sparkle power supplies.
I'm now downgrading Thermaltake to middle of the road.
Antec has two lines of PSs - the better line has a longer warranty for the same or similar capacity - the other line is more towards middle of the road.
AMD has a list of Certified (tested and found to be good quality) PSs: