on 85 watt i have 34.20 MH with Sapphire Nitro+ SE
i have test this week whole range on Sapphire Rx580 with micron, and other tab the XFX Rx580 with hynix, both can run mem @ 2300
On top from screenshot you see 1200@825mv with 2200 mem@825mv with the memcontroler on 800mv and use 76 watts on the Sapphire nitro+ SE
the XFX uses 1200@850mv wth mem 2200@825mv and mem controler I/O on 800mv
Micron strap on 2000: 777000000000000022AA1C0073626C41B0591016BACDC6090060060004061420EA8940AA030000001914292EAE2E3B16
for max 2300 mhz ram clock ( here is polaris not stable on timings above 2100 mhz ram )
Sapphire uses Polaris 20 XTR and the XFX Polaris 20 XTX
XTR from sapphire is not efficient.