Drivers worked for me with some effort. Windows 10, 3 580 Gigabyte Aorus 8GB. Stock voltage was 1125mv.  

Out of the box, no luck with voltage control through Wattman. The Afterburner beta was able to bring the voltage down 96mv from stock, but it would quickly glitch and massively drop hashrate or hang.

Went in, flashed the bios with new voltages--875mv for each state, and I changed the top state from 1365mhz to 1125mhz. Raised memory speed to 2150mhz, stock memory timings.

Rebooted. Brought me down to 950mv.

I then went through Wattman again to change the memory controller voltage from 950mv to 875mv. Success! All three cards are again running at 1125/2150 and using 863mv. Temps and power consumption are now identical to what they were prior to the beta driver.

When I purchased the cards in May, each got around 26.7mh/s (~81mh/s total) under the above settings. That had dropped to ~24.5mh/s (~73mh/s total) prior to installing the beta drivers. Now, with the beta drivers, I'm back at 26.7mh/s (81mh/s total) over the last 24 hours.

I'm currently at 19 days on a ticket for missing ETC deposits (on the blockchain, but haven't hit Poloniex). No response, no resolution. Frustrating.

I replaced the 2000mhz timings on my Nitro 470 8GB with the 1750mhz timings and successfully flashed.

At 1125/2100, Eth mining went from 26Mh/s to around 28.5Mh/s, with a slight increase in DCR as well. Pushing the ram up to 2175 brought me close to 30Mh/s. Nifty, right?

There's one thing that concerns me, though--in HWiNFO64, with the updated timings, the "GPU Memory Controller Utilization" readings are alternating between normal black text and gray text (gray and static figures 90% of the time, then brief changes to black when the figures update; this is the ONLY line that does so). It also appears that GPU memory errors are not being reported correctly (was getting more errors at 2100mhz with the 2000 timings than it was showing at 2175mhz with the 1750mhz timings). Also, when starting HWiNFO64 while mining, it typically takes several additional moments for the "GPU Memory Controller Utilization" line to even appear.

With stock timings, none of this behavior occurs. Text is always black and all lines appear at the same time when HWiNFO64 is started.

Any ideas what's occurring? Could the changes in timings potentially damage the memory controller?

Any idea what expected reject rate should be? Seeing >10% after a couple of hours of mining.

I'd recommend being very cautious when increasing voltage with V9, given the increased power use from spikes.

Same settings V8 vs V9 on my Fury Nitro (1140/550, -12mv), GPU CORE POWER:

V8: AVG 207W; MAX 274W

V9: AVG 210W; MAX 370W

Only a 3W difference in AVG, but a nearly 100W change in MAX. Big difference to begin with, and enormous in an multi-gpu setup.

(As it stands, undervolting to -96mv and reducing clock to 1110mhz saves me 40W on average V9 vs V8, but the MAX is higher in V9 even when significantly undervolting from V8 (283W vs 280W))

Just to share what I've been observing with the "power spikes" and HWINFO64. Spikes seem to occur every 5-6 polling intervals (time = 100ms)

V9 (Intensity 8 ):

Fury Nitro:

1110/550, -108mv, ~352 S/s;

GPU Core Current: AVG 153A, but spikes as high as 247A

GPU Core Power: AVG 173W, but spikes as high as 280W

1140/550, -12mv, ~360 S/s;

GPU Core Current: AVG 175A, but spikes as high as 310A

GPU Core Power: AVG 210W, but spikes as high as 370W

RX470 Nitro 8GB:

1300/2100, -100mv, ~223 S/s;

GPU Core Current: AVG 78A, but spikes as high as 126A

GPU Core Power: AVG 78.3W, but spikes as high as 126W


V8 (Intensity 4 ):

Fury Nitro:

1110/550, -108mv, ~300 S/s;

GPU Core Current: AVG 145A, but spikes as high as 192A

GPU Core Power: AVG 165W, but spikes as high as 218W

1140/550, -12mv, ~310 S/s;

GPU Core Current: AVG 180A, but spikes as high as 224A

GPU Core Power: AVG 207W, but spikes as high as 274W

RX470 Nitro 8GB:

1300/2100, -100mv, ~190 S/s;

GPU Core Current: AVG 75A, but spikes as high as 99A

GPU Core Power: AVG 74.5W, but spikes as high as 99.6W