Originally Posted by generaleramon
I think the rx480 has a weak memory controller(gradual increase in errors you see @stock). As you can see memory can do 2000+ mhz with VERY tight timings, but with the stock ones errors start to appear @2150-2175(my card at least), adding volts to the imc does not help. With my timings you gain 5gb/s every 25mhz. I can do 240GB/s @2125mhz but errors start to appear(1000mv imc) i have to test it @1025-1050mv to see if it's any better.
Anyway, yes you have the same performance of a 2250mhz overclock but with a frequency that the imc can support and using low voltage (testing 925mv).
I think it's both the IMC and VRAM chips, as I have seen improvements after improving cooling on both. Previously I was unable to clock the memory (with stock timings, obviously) past 2200MHz, and even then it needed 5-8C air going into it and 2500RPM fans. After applying a heatsink I can do 2250MHz (with errors, but it doesn't crash), with fans spinning at about 1000RPM and a more reasonable air temp of 18C. And error rate at lower frequencies has decreased.
I haven't noticed any benefits of increasing IMC voltage either.