Posts Tagged ‘bitcoin’

Free graphics card by earning bitcoins

February 12, 2011 15 comments

Well, here’s the plan.

I’ve just bought a Powercolor ATI Radeon HD 5770 for AUD$127 from in Ultimo, Sydney yesterday.

This is a good quality graphics card that is below the current 6000 series cards in terms of performance but cheap at the price.

What I plan to do is earn enough money from it to cover the cost within 2 months!

How is that to be achieved? By “GPU mining”.

With the advent of OpenCL support, the newer graphics cards can be instructed to use the onboard graphics chip (known as the “GPU”) to focus on intensive mathematical tasks and free up the main system CPU to do other things.  The GPU is designed for this sort of work so it’s an ideal way to get the most out of the hardware you have purchased.

Ok, here’s where the money comes in.  Bitcoin is a form of virtual currency that is managed by a network of connected computers on the internet that talk to each other at a peer level to manage the transfer of bitcoins from one party to another.  The transfer is anonymous in that you know the identifier of the party you are dealing with but not who they are. There are businesses that are accepting bitcoins as a form of payment. The computers in the bitcoin network belong to any individual that is interested in partaking in the bitcoin economy.

My computer is now one of them.

Every now and again, one of the nodes (i.e. computers) in the network creates some new bitcoins (50 at a time to be precise).  The more processing power you have, the more likely you are to create a block of 50. By adding this graphics card, I have increased my processing power for bitcoin generation by about 150 times and should create 50 within 8 days on average according to the bitcoin calculator. I am processing at 155 Mhash/sec now.

There are markets to swap bitcoins for USD through paypal transactions which at time of writing show that 1 bitcoin is near to USD$1.  I will earn USD$50 per week on that basis which will pay for the card in under a month but I’m being conservative by aiming for 2 months. There has been a significant rise in the relative value of a bitcoin in the past 6 months which is a critical factor in this plan.

In order to get things running on Ubuntu 10.10 64-bit “Maverick Meerkat”, I had to download and install the proprietary version of the ATI driver (10.11 is the best for performance currently) for my card.  It chose the radeon driver by default which does not provide the OpenCL support required. Also, I chose ATI since their performance for mining is far, far better than Nvidia’s.

It was necessary to also get the ATI Stream SDK 2.1 from here.  This provides the OpenCL libraries.

I also downloaded this to get the correct ICD files installed under /etc/OpenCL/vendors

This how-to for Maverick Meerkat and also this link were invaluable in getting to this point.

Having achieved that little success, now we need to get the bitcoin software and also the Diablo GPU miner software.

You should ensure that the bitcoin server is running rather than the actual user interface (see below).

In a terminal window, run the following

sudo gedit ~/.bitcoin/bitcoin.conf

and put in any values for rpcuser and rpcpassword



Then you need to run the bitcoin server with

bitcoind -server

Now finally you need to run the Diablo miner making sure that it knows where the ATI Stream SDK OpenCL library is. (find it with sudo find / -name and using the path to where you downloaded the miner along with the username and password you put into the bitcoin.conf earlier.

export LD_LIBRARY_PATH=~/Downloads/ati-stream-sdk-v2.1-lnx64/lib/x86_64/

./ -u myself -p somethingsecret -w 64 -f 10

This should then show the current processing in terms of khash/sec.  Mine is between 150,000 and 160,000.

Now to sit back and see if I improve on my free 0.05 bitcoins in the next 8 days (UPDATE: First 50 bitcoins arrived this morning, 27/02/11 4:14:49 AM, after about 15 days of processing)

Oh, and if you do manage to get some coins and fancy giving them away, my bitcoin wallet is 1Cfdc5DHMABv27eyQ9xcrnuynQmx9dRXTg