Digilux 600w hps

Ive ran my 600w Digilux hps bulb for 3 harvests now, should I change out to a new bulb or how long is it good for? I'm running it vertically in a 4' wide closet with my girls about 2 fist lengths away to about 2.5' away. I thought the manufacturer said it was good for a year but is that really true?


Thanks.