I have a problem with Hashrate very low.. I only get 5MH/s

I have a problem with Hashrate very low.. I only get 5MH/s

I have two GPUs (rx 570 4 GB) that I use for mining Ethereum(ETH),One connected directly to the motherboard and the second is connected via Riser

The first give me only 5MH/s And the second 29MH/s ,Where is the problem?…I am using the latest windows update and driver card and PhoenixMiner 5.1…Please who has a solution , and thanks to everyone