Actually that other thread had pics of my 5700 settings not the 570. Here they are:
I set my Core Frequency at 1200mHz for both State 6 and State 7 (although I think State 7 is only used in 3d rendering so State 6 is the max level used when mining). I set the voltage at 875 mV (although some of my GPUs will run stable 5-10mV lower).
Then there is the VRAM settings. I only go up to 2050 mHz and again I set the voltage at 875mV. All of this gives me 30.9mH/s for a power consumption of 86W per GPU.
You should be able to get your Memory clock up to at least 2100mHz on a 580 - again just wind it up until you start getting artefacts on the screen (or it blue screens in which case it will all reset when it restarts) then wind it back a bit. Same goes for voltage - lower it in 5-10mV increments until it fails then you will have found your limit. Stress test it for a number of hours - probably need 12-24 hours of smooth running to make sure you are not going to have issues. If you do, look in the miners log and find which GPU failed and ease up on its settings and try again.
Couple of things to remember - you will be able to get higher hash rates for more voltage, but it’s usually not worth the extra power and you also start to get an increasing number of rejected shares from the miner.
The second thing is that all GPUs are different. Of my 12 RX570s, 9 of them use these settings without any problems but the other three need a little more power or a little less memory speed, otherwise they crash regularly.