How much watt is this SPS has?

244w max on the 12v where it matters.

It not a good psu at all.

The gt710 actually only requires around 30w peak power

Irregardless of the rest of your system, looking at it youre running an intel cpu & maybe a couple of drives ??

The psu has plenty of wattage to run those specs, its jusy not very good quality.