Novolog is faster
The '70' portion of both is same, but the '30' portion of NovoLog
has faster onset of action <15 min vs about 30 min for novolin
Otherwise, unit for unit they are about same. The NovoLog thus can be used right before meal, novolin (insulin) should be about 15-30 min before meal. So just timing is different. Consult doc. Good luck.