Can someone help me with my really low hash rate please?

I have a few rigs running Ethos and Claymore 11.3 and the hashrates for XMR per card are about +/- 700. Cards are RX470 and RX580. I have a Windows 10 rig with 6x RX 480 cards that I've now installed Claymore 11.3 on and got it up and running, but the cards are only hashing at about 370 each which is almost half of what they are doing on the Linux machines.

I can't figure out why. Cards have modded BIOS as per the other ones, core 1110 and mem 1980 and the same cards that are running double the hash rates on my Linux rigs.

My config is as such:

setx GPU_FORCE_64BIT_PTR 0
setx GPU_MAX_HEAP_SIZE 100
setx GPU_USE_SYNC_OBJECTS 1
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_SINGLE_ALLOC_PERCENT 100
NsGpuCNMiner.exe -xpool ssl://xmr-eu1.nanopool.org:14433 -xwal  MyWalletAddressEtc -xpsw z -pow7 1

Thanks