hi
my rx580 8gb stop mining ETC at #379 epoch (4GB DAG size) in win10 & PhoenixMiner 5.1c
but still work ETH at #368 epoch.
my driver is Crimson Beta for Blockchain.
i dont have any problem in linux but some rigs work in win10.
any suggestion?
 

Good drivers. These are versions from 18.12.1.1 to 19.7.5 (inclusive), and from 19.12.2 to 20.8.1 (inclusive). These will allow you to mine until DAG epoch 372-373 and won't need restart of PhoenixMiner on each DAG epoch change.
Not so good drivers. These are versions 18.1.1 to 18.10.1 (inclusive), and from 19.8.1 to 19.12.1 (inclusive). This will allow you to mine until DAG epoch 365-366 and will require restart of PhoenixMiner on each DAG epoch change (for these drivers this will be preformed automatically unless you have added -dagrestart 0 command-line option to explicitly disable the auto-restart).

Having dag issues with 2x AMD RX 580 8Gb cards with the latest Claymore ver. 15. Windows 10 is using around 3.6Gb total when mining then when it creates the dag which is a additional 4.0Gb it pushes it over 8Gb so therefor the AMD 8Gb cards can no longer mine ETH though NiceHash which was what I was doing until my computer crashed so bad I had to reinstall Windows 10... Long story short The Claymore Developer needs to update Claymore to support a total of 8Gb GPU with the GPUs on a little under half load. I've took countless steps to try and remidey the problem but no such luck... That includes uninstalling the latest version of NiceHash Installing again, reinstall diffrent versions of NiceHash, Set my Virtual Mem to 30000 and uninstalling and reinstalling diffrent versions of the AMD Drivers starting with 19.7.5, 19.10.2/3 and 19.12.3. Still same outcome, Can not create big dag for GPU openCL error and tells me to restart miner which I have also done countless timesiss.