Variable speed ETH Radeon RX 550

[benjamin07]

Hi,

I got an AMD Radeon RX550 4GB and I am using ethminer, I get variable speeds: https://ibb.co/b6Bb45

Here is the batch file:
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
ethminer.exe --farm-recheck 200 -G -S eu1.ethermine.org:4444 -FS us1.ethermine.org:4444 -O <wallet.worker>

Is there anything that can be done to improve or stabilise the speed?

I also got an AM Radeon R7 250 4GB 512 stream pocessors: it was doing only 1-2 MHs...