I think your PSU can pull it. The 5700XT is rated for 225 watts at base clock and your CPU is rated for 65 watts. You can also generally say the rest of a system is around 100 watts in consumption, barring lots of extra hard drives, bringing it to a total of about 400 watts. Note that you will probably not be able to overclock that hard though and that if you decided to overclock, you may need a better PSU.