I read from this post that it is possible to get 43 MH/s using AMD Radeon HD 7990. Does anyone know how can I achieve this? I am getting right now 30MH/s per card using EthOS.
Any help would be greatly appreciated.
I've gone to the link http://www.mininghwcomparison.com/list/index.php?brand=both and filtered for 7990 and the top 5 entries relate to Ethereum mining:
Clicking on More Info on the fourth entry, then clicking on Config provides the following information:
--cl-local-work 128 --cl-global-work 8192
So this miner is using a Powercolour HD7990 with the core clock at 1,000, mem clock at 1,500, Windows 10, driver Catalyst 15.12 AND they have configured their
ethminer application with the two additional parameters listed above.
These parameters are not necessarily the same across the same GPU models from different manufacturers.
You will need to change the values of both parameters and then measure the hash rate, choosing the best configuration for your situation - as this parameter affects the electricity consumption levels and the heat generated.
The same applies to the clock and mem speed. When overclocking you will find a spot when your GPU stops working correctly. Be careful when overclocking - there is a small chance you could fry your GPU.
I have not used the alternative genoil miner, which is apparently more configurable and performant. Search on this site for "genoil" for more information.