With that CPU and videocard I will never use a 300W especially not e generic... both use lots of power so I recommend atleats 350W but even then it is probably running on its max... 400W+ would make your PC more future proof.
My CPU fan spins so fast that it creates a wormhole
You can get a high quality Fortron 350W power supply with over 400W peak output at Newegg for only $32. Better than an Antec or Enermax 350W unit, and cheaper too! So why risk using a 300W (anything) when such a good supply as this is available for so little money?
<font color=blue>Watts mean squat if you don't have quality!</font color=blue>