I have an asus rx480 dual oc 4g which i'm using for mining. It has some nice samsung memory which will easily overclock to 2000 mhz. However, I've noticed some very random behaviour. I've got it to hold the 2000 mhz setting, but i doesn't have any effect on my hashrate, except for 2 instances where it did dramatically. What i mean by this, is most of the time when the memory is overclocked to 2000mhz it will show the barest improvement to my hashrate (say 24.60 to 25.00 mh/s), but sometimes I can get it to improve to 28 mh/s easily with the same settings. I am using 2 asus rx480 dual oc 4g cards in the system. The first time I installed the 2nd card (the one i'm overclocking), i set it to 2000 mhz and it worked fine, 31 hash-rate, but after I rebooted the hashrate reverted itself. Upon re-installing the drivers again, after using ddu, it went back up to 31 mh/s. However, ever since then I've been unable to affect the hashrate by reinstalling drivers at all, changing settings, or whatnot. I'm using claymore miner for ethereum. I'm using hwinfo to verify that my vram clocks are what i've set them to.