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- Run 18.6.1 for less power consumption or 18.5.1 for higher hashrate (marginal differences both).
- Use MSI AB to "extend official overclock limits." Q: are you using MSI AB or ODT to control the fans? I greatly prefer using AB to set a custom fan curve.
- Bump up PL in AB to +5%
- Use ODT 0.2.5 to set highest P state for core/mem clock/voltage, trying 1180MHz/895mV for core and 2000-2100MHz for mem. Q: What about memory voltage?
- Set intensity manually in SRB try 23 to 24 initially. Q: What about worksize? SRB is setting it to 32 automatically (also, double threads true and K auto set to 1).
And that should bring my power consumption down to around 40W per card with a slight boost to hashrate, correct?
Depending on what brand 560's you have, they may not be able to go down to 40W and retain 450 h/s, it all depends on how well they can undervolt. I think it's impossible with the 18.5.1 drivers you must use 18.6.1 or no dice. For me 18.5.1 read 40w on gpu-z if I had tested on the wall I'm sure it would actually be 44-45w. 18.6.1 read 36w on gpu-z and goes no higher than 39.5w on the wall for me. The tiny ~5 H/s gain on 18.5.1 is definitely not worth the higher power draw. If you're desperate for lower undervolt you could try lower core clock than 1180, but at this point every step down is negative for hashrate.
I just use ODT at fixed fan speeds, my 6x rx560 2gb rig is in my bedroom so I try to keep it quiet like 1600 rpm, as long as my cards stay 65C or under it's okay.
On v7 I got max hashrate with -10% power limit. On v8 I have to increase to +10% for max hashrate. PL doesn't really effect consumption, the core voltage effects it most.
On v8, my 560's need 865 mV on mem voltage to be 100% stable, at 860 mV they can crash or lose hashrate after many hours. I had it on 860 mV before because it was stable with older v7, so v8 needed +5 mV.
Try 8 worksize first and then 12/16 and see if it improves hashrate, doesn't make sense for a 2gb card to go any higher than 16.
Holy cannolis did I make myself a metric craptonne of work for myself yesterday. In directly violation of the scientific method - change one variable at a time - I DDU'ed 18.5.1 and installed 18.6.1, then moved the RX 570 from my main desktop over to my 4x RX 560 mining rig, then proceeded to spend the next 4 hours trying to get the mining rig to not crash running either SRB or xmr-stak. I finally gave up on the RX 570 but it wasn't a totally wasted effort: now I am getting 1840H/s out of the 4x RX 560 rig at the same 355W total from the wall (55W actual per GPU) running 18.6.1 and manually setting worksize to 8 (but letting SRB set the intensity, and still with double threads true).
And of course this morning I see there is a new version of SRB out, but I am too shell-shocked from yesterday to even contemplate messing around with this today.
Oh, and I didn't even get to the point of trying to tweak voltages with ODT; the miner needs to run for more than a few seconds to bother with that kind of optimization.
At any rate, thanks for help!