Hey fellow steemians!

I told you in my introduction post that I considered building my own mining rig.
Well now it's done and operational!

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I - The hardware :

First of all, I made a list of all the hardware I needed :

• 1 x SSD 120 Go (62,80 €)
• 1 x Motherboard MSI Z170A SLI PLUS (125,91 €)
• 1 x Intel Pentium G4400 (61,94 €)
• 6 x EVGA Geforce GTX 1070 SC Gaming 8GO (2555,7 €)
• 1 x Corsair Professional Platinum series HX1200I (275,95 €)
• 6 x USB 3.0 PCI-E Express Graphics Extender Riser Card Adapter Power Cable (53,94 €)

Now finding these pieces at the cheapest price and ordering them in France was one of the hardest and longest parts. The total cost reached 3191,76 € including the shipping price.

II - The custom built casing

I first designed the casing with sketchup, using the dimensions of the hardward I had ordered.

It's made out of wood because I had scrap wood for free and available :

It took me about 2 days to build :

III - What I'm mining and the software I'm using

The OS :

I downloaded windows 10 professional directly from microsoft and installed it via a USB flashdrive without an activation key (I heard we don't need one for mining).

Steps you should take when installing the 6 GPUs :

It took me a while to figure this out, searching though the different forums and youtube videos for help :

• Flash bios and Install the latest release
• Do all Windows updates
• Connect only one card with a USB-Riser and install the drivers from the provided CD. Open the device manager and take a look at the Graphic section. Only if your graphic card (GTX 1070) is shown there, driver installation is finished.
• Restart the computer
• In the BIOS change ‘PEG0’ and ‘PEG1’ values to ‘Gen1’ and Set ‘Above 4G Decoding’ to ‘Enabled’
• Save et reboot, check if everything works fine.
• After this, connect the next three cards, open the device manager and take a look at the Graphic section and waiting until NVIDIA GeForce GTX 1070 is shown for all four cards, it might take a while and screen can go black (but it will come back).
• Connecting the last two cards - restart and it's done

Dual mining ETH + LBC :

For the moment I'm mining dual mining Ethereum and Lbry using claymore mining. Ethereum seemed the most profitable, even though the prices have crushed and ethereum ice age is on it's way (just my luck). I didn't see much difference in the altcoins though, I didn't test the hashrate of all the altcoins, but Libary just seemed slightly more profitable.

• The mining pool I'm using for Ethereum is ethermine.org
• The mining pool I'm using for LBC is coinmine.pl

The script :
GPU_FORCE_64BIT_PTR 0
GPU_MAX_HEAP_SIZE 100
GPU_USE_SYNC_OBJECTS 1
GPU_MAX_ALLOC_PERCENT 100
GPU_SINGLE_ALLOC_PERCENT 100
EthDcrMiner64.exe -epool eu1.ethermine.org:4444 -ewal /Your_Ethereum_Address/./RigName/ -epsw x -dpool stratum+tcp://lbc-eu.coinmine.pl -dwal /username/./worker/ -dpsw /Your_lbc_password/ -dcoin lbc

Overclocking

I overclocked my GPUs with MSI afterburner.
Core clock : +69
Memory clock : + 512

This configuration is stable, allowing me to have a hashrate of 176 MH/s on Ethereum and 160 MH/s on LBC. I could do more but I'm afraid I'd be damaging my graphic cards in the long run.

The return

On average I generate around 0,06 eth per day which means about 1,8 per month. At the current price of 224 €/eth according to cryptocompare.com, I should be making about 403 euros.

On average I generate around 3 lbc per day which means about 90 per month. At the current price of 0.0001340 btc/lbc (0,2786 €/lbc) according to cryptocompare, I should be making about 25 euros.

Considering the electricity cost at about 140 euros, I should be making a profit of 288 euros per month. So at the current stage, it should take me about a year to gain back what I spent. However, with the difficulty of ethereum increasing exponentially, I most probably will have to change the cryptocurrency that I'm mining. Probably zcash.

I expect ethereum to reach a very high price so I won't be selling most of my ethereum.

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If you have any questions or advice please share.
Thank you for reading,
Kind regards,
@ronahi