Use the lastest amd blockchain driver if you aren't into gaming or try finding BIOS for your gpu and flash, this is the most stress relieve solution instead of battling with clock speed
Blockchain Compute Driver for Windows is currently not relevant for mining, because it does not support a dag file larger than 4 GB
https://www.amd.com/en/support/kb/release-notes/rn-rad-win-blockchain-betaChanging the driver will not give a higher hash rate, you need to use more aggressive memory timings.
But 30 megahashes is a good result, 33 megahashes could only be obtained on RX 480 with Samsung memory