yesterday Windows 10 installed a security update (even tho we disabled updates under services)  which took down most of our miners from 30 hash/card down to 20 hash/card.

After a day of troubleshooting we found the resolution>

our setup is
asus H270 Plus MB
Sapphire nitro RX580 - 8gb (hynix)
AMD aug23 driver

bat file
1140/2150 845mv

single mining ETH 930watts 180 hash (6 cards)

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Solution for windows 10 update causing hash to slow to 20 hash per card>

1: go to device manager, install AMD aug23 driver manually (right click a card under display adapters, choose update driver, then CHOOSE from device then click "HAVE DISK" then go to c:/AMD, drill down thru the aug23 driver, install it.

2: run atikmdagpatcher.exe

3: reboot

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