GPU load on a rig 5 GPUs

hey guys,

i just started to mine ZCASH and i had 2x 280x mining 570H/s @62% gpu load. Now i bought 2x 7870 to it plus a 270x i am getting almost 1.1kH/s but the GPU load on all cards went to 98%. any idea why it happened ?

thank you

nobody any ideas ? the only reasonable explanation which i can think of is that the load was lower because i had gpus of the same sort.

anybody here with a mixed cards and lower GPU load ? or anybody with the same ones 4-6 280x and lower GPU load ?