The latter is fine - for most Windows systems we have platform 1 when an Intel CPU is there.

Can you check on CPU load with all 7 cards? If the overall system load is >70% this may reduce speed because the Miner does not get enough attention by the operation system and thus the work is not scheduled fast enough.



It can be that your system runs out of memory. The Windows AMD drivers (not sure about the Linux ones) require that at the creation time of the GPU buffers there is as well RAM or virtual system memory available as requested GPU device memory. So with HIGH this means that virtual memory file has to be about 7.5 GB per card!

This video gives a good hint, how to increase virtual memory size on your system (For lolMiner it should be more then the 16g in the video, but the way to set it is the same) :
https://www.youtube.com/watch?v=ZL0m7tVt_DU

You could also try running less cards or --set-work-batch 2G instead of --set-work-batch HIGH in the beginning. Would like to know if this changes your cards from not working to working

Edit: Other reason indeed can be some driver issue - there is reason, that on Windows the default is 2G instead of AUTO or HIGH ... just because we had some trouble with AMD driver ...