With 1.6.3 the same situation as with 1.6.2... On cn-v7 RX 580 8Gb max speed is 1000 h/s on intensity 108, but not every launch. Miner needs to several starts to get this speed. Waiting up to 5 minutes not helps. Mostly speed is 985 h/s. On 1.6.0 speed is up to 1035-1040 h/s with intensity 116-117.
On v7 all of my cards , 470, 480, 570, 580 4gb or 8gb they all get the same speed on every launch, this is how it was in earlier versions too, only heavy had this 'have to run multiple times' to get max speed thing.
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Hi dok! Little trick for get hashrate on new drivers same as on blockchain drivers. Setup old blockchain beta drivers, clean up the cache folder, start SRBMiner, after compiling kernel file stop the miner. Setup new drivers like 18.5.1 or latest and start SRB. Hash rate will be same as on blockchain drivers and less power consumption.