gpumining
I have RX480 and RX580. Two GPUs together giving stable 23,4Mh each.
I'm using linux so clocking them will require playing with bios which I'm bit afraid to do.
Can I run them like that, without any modification for a long period ?
I prefer stability over high hashrate now.
Thank you
UPDATE: The problem was with the drivers. I got the latest ATI drivers (Crimson 13.2 hotfix for windows) that solved the problem. I'm getting ~21MH/s per card.
GPU
For the highest hashrate per GPU, the answer is the AMD HD 7990 (minimum hashrate 43 MH/s), followed by the AMD R9 Fury X (minimum hashrate 28 MH/s).
The HD 7990 was released in 2013 and is harder to purchase from stores as this series has been superseded by the R9 series released in 2015. Internally, the HD 7990 with 6Gb RAM consists of two AMD HD 7970 GPUs with 3Gb RAM each packaged together.
Note that your Ethereum mining software will treat the HD 7990 as two separate GPUs with 3Gb RAM each, and miners with 2Gb GPUs have recently encountered some problems with the growing DAG file size 2Gb cards stopped working - 13/03/2016.
From AMD HD 7990 vs AMD R9 Fury X, here is a comparison of some key features of the HD 7990 (left) vs the R9 Fury X (right):
Other parts of the system
The main part of the mining hardware is the graphics processing unit (GPU). Here is a link to a site that allows you to compare the different GPUs - http://www.mininghwcomparison.com/list/index.php?brand=both . Type "Ethereum" in the filter.
In general, the best current GPUs are the AMD R9s. But the answer is more complicated.
What do you want to optimise for? Lowest upfront cost per unit hashrate? Lowest ongoing cost (upfront + electricity)? Best hashrate per unit electricity? Lowest heat (and electricity) per unit hashrate?
And all this depends on the cost of hardware (it's all relatively more expensive in Australia) and the cost of your electricity (also relatively more expensive in Australia).
For the lowest heat (and electricity) per unit hashrate I would say the R9 Nano.
For best hashrate per unit electricity I would say the R9 Fury X.
For the lowest upfront cost, possibly the R9 290.
If you are considering the superseded AMD HD range, the HD 7990 gives you the highest hashrate as this is essentially 2 x HD 7990 GPUs packaged as one. It is harder to find stocks of these units now.
I've gone for the R9 390X.
You don't need a fast motherboard and CPU. AMD CPUs use more electricity than the equivalent (by performance) Intel CPUs. But AMD CPUs are cheaper than the equivalent (by performance) Intel CPUs.
Bill Of Materials
Your bill of materials will consist of:
Build a list with expected hashrate and cost in a spreadsheet and work out the best for your situation.
My Setup
Here's my meagre setup that produces 52 megahashes per second without overclocking, 63 with. Cost in Aussie dollars. It's not the best in many ways, but it works:
Other Considerations
It may be cheaper to buy ethers on an exchange. You may have to buy bitcoins with your fiat currency and exchange your bitcoins for ethers.
Also, the number of ethers you can mine is limited by the "size" of your rig, whereas buying ethers will be limited by the size of your wallet.
Here are two Ethereum mining profitibility calculators:
The difficulty in mining ethers is going up as more people bring online their miners and the price of ethers in the future is uncertain.
The Ethereum network will be moving from the current proof-of-work to proof-of-stake where the GPU miners will all become obsolete, and the date of the switch is uncertain but may be in a few months.
It is very easy to burn out your GPUs - I've done in two, but luckily got warranty replacements. The first just stopped working after one day. And one of the fans got "sticky" in the second one after a few months.
For me, my aim was to find out more about the Ethereum network as I am a software developer and the possibility of programming smart contracts is like playing with a giant box of Lego Mindstorm, with unlimited pieces.
Happy hashing.
Here's Rasterbator, my 11.828 TFLOPS Ethereum mining supercomputer with my dog for scale. And yes, it is a long tongue.
Best Answer
Hi those are somewhat lower hashrates than expected for RX480 and RX580. I can't advise regarding Linux, but on Windows with Claymore miner and WattTool you can both undervolt and get better hashrates, along with stability. On Windows you won't need to modify the BIOS unless you really want to (memory timing for Polaris).