I just wanted to chime in with my current hash rates of some of the cards I'm using.
Please note that I haven't really optimized that much, I've only modded the memory straps in the bios' and then underclocked core and overclocked memory with SimpleMining.
6x Sapphire RX 570 Pulse Mini (ITX): 28.10MH/s ETH + 420MH/s SIA. 1500 straps, 1106MHz core clock and 2000MHz memory clock. Have powertune set to 1 in SimpleMining. Hynix memory.
4x Asus RX 570 Expedition OC: 27.15MH/s ETH + 430MH/s SIA. 1500 straps, 1180MHz core clock and 1900MHz memory clock. Have powertune set to 6 in SimpleMining. Elpida memory.
I just set up the 4x Asus cards while I'm waiting for risers to be delivered. I still have 14x more Asus RX 570 Expedition OC and 12x Asus RX 570 Strix Gaming OC to go through but I'm waiting for risers.
Not bad! What memory brand?
You can do better with performance timings, if you have Samsung use Uber-mix 3.1. You can PM me, I have plenty of timings for every memory brand, also I've made bios tutorial.
xfx black RX570 4gbs with elpida..not time to play yet,but first shot with 1200/2000 975mv and some other small changes with power limits.. has been stable 7-8hours @29.9mhs..GPU-Z says 83-85watts.. used a custom strap from my xfx black 470s, i found it on the custom timings thread here.its faster by 1mhs then the stock 1500. will let you know how far i can push them...my asics are from 74-88 mixed.
ELPIDA -xfx black 4gb..works on 470s and 570s ..best strap iv found so far. i didnt make it,forget who did..just sharing,good luck.
777000000000000022AA1C00315A5436A0550F15B68C1506004082007C041420CA8980A9020004C 01712262B612B3715
Yep, Elpida is good I like them too, right behind Samsung. 30MH/s is pretty good, my Elpida does only little bit above 29MH/s, maybe it could be higher with better Claymore config, I'm mining Monero.