He needs around 50 more watts over 500. 500 is the minimum recommended for that particular card, then if you had a 75-95w CPU at full load on top of that, drives, fans, possible overclocking ect. Even if the PSU is 80+ that is only giving it an 80%+ efficiency up to 500w meaning he will be damn near capping in wattage for a while. If it was say, a TX or HX then I wouldn't say anything. Since he put the 620w in his list that is MUCH better.
BF3 will run low to medium settings depending on your monitor resolution.