Quote from: Emoclaw on June 04, 2017, 12:51:11 PM

What really matters is the memory they have and what memory clock/timings you'll be able to achieve. So get the cheapest of the three because memory chips are a lottery.
You should definitely read up on modifying the BIOS. Being able to copy memory straps would be great, modifying the timings by yourself would be even better. Generally you should be able to achieve 2000MHz+ memory clock with a timing strap of 1500MHz for Hynix or Micron or 1750MHz for Samsung or Elpida.
I'd suggest starting from these threads:
http://www.overclock.net/t/1604567/polaris-bios-editing-rx5xx-rx4xx (the first post)
https://bitcointalk.org/index.php?topic=1758267.0 (the entire thread, probably)

Stock settings will get you 22-24MH/s on all these cards on ETH at ~150w, modified BIOS and overclocking, as well as core undervolting and underclocking the core, will get you 28-31MH/s at ~90-100w.

ethOS is just a plug and play solution and does not yield better hashrates, though may consume less power when compared to Windows. Use a normal Linux distro instead and save $40.

Other than that, think carefully about your motherboard and remember that if you order multiple cards that are the same (Nitro+ for example), the memory chips may be different so you can't flash the same BIOS on all of them.
It'd be best that you get at least an 80Plus Platinum PSU for a superb efficiency. Though mining is profitable even with $0.20 electricity.

They are all around the $400 mark so you're saying that they will all do the same rate until they have been clocked?

Thank you for the link - I will definitely have a read up on it and look into pushing more out of them!

So it's not really worth getting ethOS? - I'm fine setting it up on linux have done that before - can it easily be set up however to keep an eye on the rigs remotely ?

sorry for my naivety here - but how would the chips be different? surely if I order the same they would all come with the same that would be able to flash them?

I already have a motherboard and PSU etc that I can use in the mean time - I'll have a look into a better motherboard for more GPU's at a later date.