I'm about to try OverdriveNT, but just to undervolt (I now hate Afterburner, it keeps lowering my hash rate before I even do anything). 

I had to get the right version of Polaris, but once I did, the one click let me squeak that extra few mega hashes total 113.025 avg 28.25 now! That one click is nice!!! 

Still using blockchain driver.  I hear the adrenalin is now better, but no worse in computation only setting.

In fact the only one bringing the avg down is the RX570 Asus mining gpu amazon is slinging now. i swapped my other asus for it but regret it (gimmick.. don't buy. no resale value and not much cheaper. hash rate is only 25.146 overclocked)

Dude.. I can't believe I never noticed the switch..  I revved it up my XFX XXX samsung/micron up to 30.746 mh/s (ETH Only) on Claymore's.
My samsung/hynix xxx is up to 28.362 mh/s which is a huge improvement so I'll take it!

Thanks!

Update, using hwinfo, discovered my MSI afterburner settings wasn't optimal, but overclocking barely made a difference and caused too much instability to be worth it.

1.6 polaris one click does work..

XFX Triple X edition (Samsung):  27.963 Mh/s ===>  29.765 Mh/s  ~1.8 improvement
XFX Triple X edition (Hynix):  22.531 Mh/s ====>  25.425 Mh/s  ~2.9 improvement
ASUS Dual (Hynix): 25.372 Mh/s =====XXXX sold before testing / picking up an ASUS Mining RX 470 4G Graphics Card!
Powercolor Red Devil (Micron): 27.692 Mh/s (not modded) ====>  28.821 ~1.1 improvement


Oddly enough, attempting to overclock with afterburner got me up to 29.9, however the cards started hanging in open CL, and for some reason hopped back down to 27.963 when I got it stable again, and I couldn't for the life of me get it back to 29 again... so i gave up on afterburner and re-modded the bios and got the 29.8 Mh/s rate back and just stuck with it!

I modded my bios using these instructions from buriedone on youtube:

https://youtu.be/JKM60VVIfRg

He has links to all the tools you will need.

Thanks for the input.  I think I will start with Edz advice: download Hwinfo64 and check my afterburner impact.

I had the adrenalin driver version installed before.  I noticed a considerable improvement using the crimson blockchain driver.. see here if you don't believe me! http://www.legitreviews.com/amds-new-mining-block-chain-optimized-driver-tested_197095

As far as one click timing...hmmm.  maybe later!

For now, I will try Edz advice, (thank you) and try to get my hash rates up as much as i can without sacrificing stability.  If my cards hang while I'm at work, I miss out.  After many headaches with dual mining, I am glad to keep my temps at around 61 degrees and running solidly like they have been. 

I'm not really upset about my hash rates.  I'm just trying to get that last ounce of performance out of my rig.

Thanks guys.  I'll let you know how it goes!

Hello.  I have built a rig with the following RX580 8gb cards (Chip brand in Parenthesis) and I am getting okay hash rates mining ethereum only on 10.6 Claymore Dual Miner on Windows 10.  I am using the Blockchain driver released by AMD in August 2017 (which improved my hash rate quite a bit on its own!)  I have modded all the BIOS except the Micron chip, by copying the 1750 strap to 2000.  I have also undervolted my core voltage to -137mV getting my power consumption down to roughly 650 watts.  Here are my other global settings on MSI afterburner:
Power limit at 0
Core Clock 1360 MHz
Memory Clock 2000 MHz

Overclocking doesn't seem to make any impact.

XFX Triple X edition (Samsung):  27.963 Mh/s
XFX Triple X edition (Hynix):  22.531 Mh/s
ASUS Dual (Hynix): 25.372 Mh/s
Powercolor Red Devil (Micron): 27.692 Mh/s (not modded)

Any tips on better hash rate or efficiency are welcomed and appreciated!