I assume you properly modded bios with proper straps.

Try these: set gen1 and enable 4g encoding at bios, install Windows 10 uefi and update it, use latest amd drivers with [Suspicious link removed]pute option, try adding to claymore command line -gser 2 -cclock 1200,1200,1200 -cvddc 1000,1000,1000 -mclock 2150,2150,2150

Lower memclock if it hangs. Try lowering core clock/voltage for gpu if its stable.