So the Tahiti based GPUs of AMD were first introduced in January 2012 and they are actually the "
Best mining GPU of all time".
They were introduced at a time when you could actually mine BTC with them back in 2012.
They were the most effective at mining Scrypt back in 2013. People were pulling in $10/day mining Litecoin and Dogecoin in late 2013 and early 2014.
They were the most effective at mining ETH back in 2016. Since the DAG was low and didn't require as much memory, you could mine ETH at 27MH/s back in Nov of 2015. And it hashed at 21-22 MH/s throughout most of 2016 before the RX series came out.
They were KILLERS at mining ZCASH when it was introduced back in late 2016 due to its huge memory bandwidth. The newer RX and Nvidia GPUs couldn't keep up.
Now as always thanks to ASICs they are no longer effective at mining ZCASH. Since they consume around 200 Watts while hashing at 300H/s.
However you can actually mine Cryptonight V7 (XMR) with them quite effectively with an bios undervolt.
Depending on your ASIC Quality (listed in GPU-z) you should be able to run these at the lowest voltage acceptable which is
0.950V and should run your Engine clock at 1000 Mhz and Memory between 1500-1600Mhz.
Make a copy of bios with Atiwinflash and Go into VBE7 and
Change #0 Core Clock to
950 Mhz and Memory Clock to
1500 Mhz, set VDDC to
956 mV.
Now restart the rig and let it run for a few minutes. If its stable then slowly increase your Core clock all the way up to
1100Mhz until its no longer stable. After a few hours, try and increase your Memory clock past
1500Mhz all the way up to
1700Mhz. Depending on memory type and straps, it might or might not cause a speed boost.
Measured from the wall at
1050Mhz/1650Mhz at
0.956V, one of my R9 280X only consumes
120 Watts from the wall. Basically same power usage as an RX Series GPU which mines ETH.
The speed in Claymore XMR miner registered is
595H/S which at the moment generates about
$0.52 USD per day. If your power costs are
$0.10 per KWH, then you should make a net profit of
$0.250 USD per day.
Post your results and lets give these amazing AMD GPUs one last hash before they are finally packaged away and forgotten...