Sorry if this was already suggested, I didn't go back. But you have Compute mode turned on? Usually that's the culprit for those low MH you are showing.
are both cards bios modded or not, what drivers are you using and please, copypaste here the bat file into the
cmd /K start /B EthDcrMiner64.exe -epool eu.sparkpool.com:3333 -ewal 0xd79745d8e38d6cE337956a7c57f7C9d343ae7057 -eworker NOM_DU_WORKER -epsw x
pause
Yes modded with ATIFlash_284 and PolarisBiosEditorMaster
pilote: 24.20.11016.4
bios is BIOS Part Number
113-2E366FU-O53
Core Clock
1340 MHz