haven't found a way to mine with my older cards (two 5870 and one 5830) for neoscrypt efficiently...i think it is only a matter of time till someone tweaks the miner for older cards, currently i'm using it to mine cryptonote with claymore miner and these three cards fetch me 754h/s compared to a single 280x h/s of ~600h/s....i remember when claymore later added support for older cards, the same will happen to neoscrypt miners..