Saturday, 26 May 2018

Bitcoin Mining

Its been a long, long time since I have posted anything to my blog. Work and personal life have gotten in the way of me adding anything meaningful to this for quite some time, so I have decided to ease myself back into it with a post on how I have been getting along with the topic de jour - mining bitcoins.

My experience with cryptocurrencies, specifically bitcoin, has been simmering away in the background of my home lab for around five years now. I started off with the most basic of kit, a simple USB miner hooked up to a laptop that probably crunched through at around 33MH/s - we will get back to what that actually means later on. It was a good intro into how mining can work, I initially set the miner up to try and mine a whole bitcoin on its own, but ended up killing it AND my laptop by accidentally passing 12 volts across a 5 volt connection on my USB hub... I was rather embarrassed by the whole thing, but I did end up learning a lot from this experience.

Dont Try To Mine A Bitcoin On Your Own

Just dont, it would probably take you a couple of hundred years. Back in the day when the concept was new, people were easily crunching through bitcoins with the graphics cards on their machines, racking up dozens of bitcoins for no other reason than they could. I am not going to get into the history of bitcoin here, you can find plenty of information on it already out on the Internet, suffice it to say that if you want to make any amount of money with bitcoin mining, then you want to get into a mining pool.

Mining in a pool means you work with others to mine those precious bitcoins as a group effort. Each member of the mining pool gets a percentage of the bitcoin depending on how much effort their miner has put in to verifying the bitcoin itself. Again, I am not going to get into the details of how a mining pool works as there is already a bunch of info out in the wild that can do a better job than I and I dont enjoy mindlessly repeating other peoples words. But, if you would like to get into mining as part of a pool, then I can seriously reccomend the one that I use, Slush's Pool, which can be found here:

I think this is one of the more popular pools, I didnt really do that much research into which is the best to join, I picked Slush as there is a copious amount of documentation available on the site on how to configure just about every miner there is. Once you have set up your account, you also get a very good dashboard that tells you the status of your miner(s) and how you are performing as part of the pool itself.

After I got over the act of killing my laptop and my first miner, I decided to step it up a gear and purchase a more serious piece of kit (and a new laptop...) to see how far I could go with this. I ended up getting a BlackArrow X1 miner from Ebay extremely cheap. As far as I am concerned, this was an awesome entry level miner for anyone interested in making some decent cash from bitcoin mining a few years back. The device is significantly different to the USB miner I previously used, that one required my laptop to be running at all times, which was annoying given the fact I needed to move it around the place depending on where I was supposed to be for work etc. The BlackArrow X1 is a self contained unit that houses the ASIC's used to do all the heavy lifting as well as a computer running Android, complete with a touch screen interface, wifi and ethernet. All I needed to do was configure it to connect to the pool and leave it to do its thing, which it did for years and made me a fairly sizeable amount of cash for what I laid out for the device and power consumption. Of course, as with all types of computing equipment, things get superseded and the same is true of the X1, which has led me to start investigating how I can expand my mining setup cheaply. This device will happily crunch through bitcoin hashes as part of a pool at around 100GH/s all day long, however this is now considered to be a low power device.

It uses CGMiner, which is pretty much the same application everyone uses when mining in a pool regardless of whether you are using a USB miner or a more powerful device hooked up to your LAN. It is easy to setup and works extremely well, Slush also provides all the instructions you need in order to get CGMiner connected to the pool so you can get up and running with your bitcoin adventure as soon as possible.

If you do a quick search on Ebay right now, you will find many, many miners working up in the TH/s range that can cost a few thousand pounds. Thats great if you have the money to invest right now, but you need to bear in mind that bitcoin is a currency and its value fluctuates on a daily basis - an investment of £1k or £2k now based on current bitcoin prices wont look like such a great deal if the value of the currency drops through the floor next week. I dont have the money to soak up such a loss and I certainly dont run a bitcoin mining farm, so I got to thinking about how I can expand my mining setup economically.

At some point last year, I was given a bitcoin miner from someone who had bought a device from Ebay, but once they received it, had no idea on how to set it up. I gladly took it and left it in a drawer up until a few weeks ago when I reaslised I needed to up my bitcoin game. The device itself is a Block Erupter v2 mining blade that apparently can run at 10GH/s, this doesnt sound that fast for a device like this, however after some research I discovered that it isnt really meant to operate on its own - its a blade that is mean to sit in a backplane with four other devices attached (well, I think four, might be one or two more) and is powered from a server PSU, it has an ethernet connection as well - note, ethernet is far, far better for mining bitcoin than USB, its a hell of a lot fast, also if you have a standalone miner that offers wifi as well as ethernet, choose ethernet, it is THE fastest connection.

Other than that, there is nothing on the device at all that would give you much clue on how to set it up, the only reason I discovered what type of device it is was after googling the only text on the PCB itself. Right now, these things are about £75 each on Ebay, however, finding the backplane for these blades is extremely hard, I have spent a week combing the Internet for one and came up blank. The last one I saw for sale seems to have gone out in January this year from an Ebay seller in the US, even if I caught the auction the seller would not have shipped to the UK, which is vexing.

So, without a backplane, how am I going to get this thing started up so I can see if it will work? Well, there are a number of truly terrifying step by step guides on forums that go through how to destroy an ATX PSU with paperclips(!) in order to power the blades on, this basically involves poking bits of metal into the PSU's MOLEX connector in order to trick the PSU into the on state and then hooking up a bunch of other MOLEX connectors that have also been cut to shreds to the power terminals on the blades themselves. There is also a lot of gaffer tape involved.

Yeah... a 24/7 mining setup that involves gaffer tape and paperclips in order to power a device that gets extremely hot... Not going to do that.

However, I do need to get power to the board in order to see if it works, it has been sat in a drawer for the best part of a year so I have no idea if it will even start up - so I am going to have to use an ATX PSU for this, but in a much safer manner. So first things first, get power to the board and hook it up to the network to see if it gets an IP (it may have static addressing by default, which I am hoping isnt the case). If this thing works, then I can start looking in to getting it hooked into Slush's pool and supplement my existing setup and, if things go well with it, I might even get a couple more added in if they are good value for money...

But please, if anyone else has one of these - think twice about how you are going to power them. I havent figured out how I am going to do it yet, but paperclips and gaffer tape just doesnt sound safe to me.