On Bitcoin Mining 5

It turned out that we would not be in my sister-in-law's house as long as previously thought. They were returning home and we needed to move out to a townhouse that we owned by January. This meant that I would not be able to bring the BFL Monarchs with us. For one thing they were too loud for a townhouse environment and too hot. They were also not very efficient in terms of electricity consumption. They are rated by BFL for 0.65 to 0.85 watts/GH but I measured them as using close to 1 watt per Giga hash including the power supply and the necessary laptop.

Bitmain Antminer U3 version 2

Looking for quiet, townhouse friendly miners, in October I bought two Bitmain Antminer U3 miners. This ASIC miner is very similar to the Rockminer R-box 1 (37GH/s) miners. The U3 however runs at 55 to 62 GH/s. Like the older Rockminer, the U3 is basically silent and put out little heat while using about 50 watts of power (plus wattage of attached computer). The problem is that every day or so these miners would become "zombies" meaning that they would stop working. This requires a hard reboot of the device (unplugging and re-plugging) and restarting the mining software. It's a hassle and not on a schedule of any kind so you don't know when you'll have to do it. So as quiet as this was, the fact that it had a problem like this and that I felt the hashrate was too low I kept looking for a better solution.

The better solution in my situation was the Black Arrow Prospero X-1 (X-1.5). The X-1 hashes at 100 GH/s or better and the X-1.5 hashes at 140 to 190 GH/s. This miner is unique among ASIC miners - for one thing it has a large fan which dissipates the generated heat very quietly and effectively. For another thing it has an Android-based touch screen for interfacing with the miner. The miner is also WIFI capable which means that you can place it anywhere in the house and it doesn't need an ethernet cable or a computer attached to it to run the mining software. It is truly a stand-alone device. Perfect! As it got closer to moving day (again!) I sold the two Monarchs which turned out to be pretty solid hashers - if a bit inefficient - and bought two Black Arrow Prospero X-1.5s. I also sold one Antminer U3 and kept one in the box as a backup. I ran the two Prosperos near the dining room in the townhouse for most of the winter and spring of 2016 and appreciated their silence and their heat generation. 

The nice thing about mining for Bitcoin at home is that for part of the year the heat that Bitcoin miners generate can (and is) used to heat your living space. One hundred percent of the heat generated will go into the air in your home. For instance, if my two Prosperos raised the temperature of the downstairs portion of my townhouse by two degrees Fahrenheit, then that is two degrees that didn't have to be heated by the furnace (electric blower and gas fueled) thus saving that much electricity and gas from being used to heat our home. This means that the efficiency of the miner doesn't matter very much in the winter or on cold days in the spring and fall because you are basically running a heater that is mining Bitcoin. It's another story when the hot weather comes but the efficiency of Bitcoin miners is going to be better than rated over the course of a year if they are used in environments where their heat is used. (Now if they could make Bitcoin miners that generated cold air we'd be all set for the summer!)

I'll cover my experience with Bitmain's Antminer S7 in the next On Bitcoin Mining.

On Bitcoin Mining 4

To continue the story from On Bitcoin Mining 3, in early 2015 I had a stack of 6 Rockminer R-Box 2 110 GH/s Bitcoin miners in my living room (which my wife didn't complain about as long as I kept them quiet) and while the heat they generated was appreciated in the winter and reduced the gas bill somewhat, it was now late spring and some of the days were mighty hot which in turn made the living room too hot. So, it was either turn off the miners (which I did do on many days) or relocate them. I decided to try the attic and add an external fan.

The attic had a pull-down stairway which made access to it easy. As you may know, attics get hot on warm days and this one could reach 120 degrees Fahrenheit (49 degrees Celsius) or more. For this to work safely I had to set things up right. I placed the miners in stacks of 2 on non-flammable porcelain tiles, placed the power supply also on a porcelain tile, aimed them all towards the center of the attic where their heat would rise to the roof vents and aimed a fast blowing fan at the back of them. I also replaced the quiet fans I had earlier installed with the original more-noisy-but-more-effective-at-cooling-fans back on the miners. Then I monitored the temperature of the attic and monitored the temperature of the miners. On cooler days and at night the miners ran from 50 degrees Celsius to 65 degrees. On hot days the miners would run in the 70s. If they approached 80 degrees (which they did on really hot days) I would shut the miners down. This setup allowed me to mine in the summer and the noise and heat were out of sight. The down-time was minimal.

Oh, and I almost forgot about the laptop PC which I had to have attached to these six Rockminers. This laptop had to be in the attic too since the miners are attached to it via USB cords and the software on the PC runs the miners. After some research into the operating temperature of laptop lithium batteries I opted to remove the battery from the laptop and allow it to run only on AC power. It certainly wouldn't be good to have a rechargeable lithium battery exploding in the attic. 

Of course, this is not an optimal setup and if you are careless maybe even dangerous. Miners can fail if they run too hot too long. But these miners did not fail, and did not run slower. I kept them under 80 degrees and they only had to last until August like this as we were moving into my sister-in-law's house to take care of it while their family had "moved" out of the country for what was supposed to be a couple of years.

This meant I would have a basement in which to place my miners and in a solar-powered house. Nice. Hello, almost-free electricity.

BFL Monarch 650 GH/s Bitcoin Miner

At the same time I had noticed that the prices had come down on the water-cooled Butterfly Labs Monarch 650 to 700 GH/s bitcoin miners. If I got just one of these it would replace the six I had and give me the same hashing power. I bought one of them off of eBay and plugged it in. I had trouble getting it to hash at the rated speed. I was only getting about 500 GH, not the 650 advertised. It turned out that I had to use a special version of the Bitcoin mining software BFGminer. Anyway I spent dozens of hours trying to work out the problem. Butterfly Labs' own software EasyMiner never worked for me. Finally I got everything ironed out and the thing was running at 650 GH/s. I decided to get another one of these (actually a 700 GH Monarch) and sell the 6 Rockminer R-box 2s. 

Due to the fact that the Monarch's are liquid-cooled, the two fans on the miner are not as loud as fans on many other miners (like the Antminers). They are also potent heaters and the basement was soon very warm. This wasn't an issue though because it was a basement and not a living space.

This is the 1300 GH/s setup I had in the late summer of 2015 and going into the fall. But, as ever in the world of Bitcoin mining, things never seem to stay the same for very long. More to come....

(Some Black Arrow Prospero Bitcoin miners for sale here)

On Bitcoin Mining 3

Bitcoin Mining Difficulty Level Rising

Bitcoin mining is a nasty game. It involves heat. It involves dust. It involves sometimes VERY-difficult-to-figure-out mining software. It's a game that continuously gets harder to play for increasingly less reward. Every few weeks, the difficulty for solving a block changes - usually it gets harder, sometimes it gets easier before making an even bigger jump in difficulty. This increase in the difficulty of solving a block has the effect of pushing the little guys of the Bitcoin mining game out. It also has the effect of making little guys into big guys as they (stubbornly?) commit more resources to the project. 

So, in general, it constantly gets more difficult to solve a block (solving a block is what generates Bitcoins). This means that if you keep the same equipment that operates at the same electrical efficiency that it will take you 3 weeks to earn the same BTC that previously took you say 2 weeks before. So if Bitcoin mining is more than just a hobby, you need to upgrade your equipment every now and then. If you want to keep earning Bitcoin you must increase your hash rate. Now, because I live in a townhouse/condo, noise is an issue for me. I don't have too many empty unused areas where I can put a Bitcoin miner and not have to hear its constant droning. As such, I can't go "all in" getting the best Bitcoin miners out there because those top of the line ASICs are noisy and heat producing and not at all "home friendly". 

Rockminer R-Box 32-37 GH ASIC miner

With noise in mind, my next miner, while still having the 2 BFL 60's was to get the Rockminer R-Box 32-37 GH ASIC miner. I loved this miner! Two or three houseflies would be louder than this miner. It was (and is) quiet and small and put out a tiny amount of heat compared to the BFL 60's. The wattage was also fairly low being between 40 and 50 watts, I think. I soon sold both of the Butterfly Labs 60's (at a loss) and bought another Rockminer. This is a great entry-level miner and at the moment they are dirt cheap on e-Bay.

Unfortunately, with these two Rockminers my total Giga hashes were now lower than before and my rate of earning Bitcoin pretty much halved - that and the difficulty is always increasing. Having these two quiet miners was Heaven compared to those loud and hot BFLs so you would think I would have doubled down on just these great little miners. Maybe I should have, but that isn't what happened. 

In my dealing with the Rockminer company I became aware that they had another miner that produced 110 GH/s at better efficiency. The New R-Box 2.0 miner is 3 times faster than the "old" R-Box, at a more cost-effective price (ie., the watts used per GH is better). More GH and more Bitcoin with less heat and less electric use per work done made buying these units a done deal for me. Add to that a few people online said they were quiet too. I ordered one to try it out.

It was not very quiet. Quieter than a lot of miners, yes, but noisy enough for a condo. Following my earlier experience with the two BFL Singles, I decided to swap out the two original internal cooling fans for two quieter fans. The fans were indeed quieter but also a little slower which meant that the unit ran a little hotter than when I got it but well within the safe operating temperature range (maybe 10 degrees C warmer). Now I had a 110 GH miner which ran pretty quietly and with just moderate heat output into the room. That heat output was appreciated anyway since it was winter and the heat added to the warmth of the house. Win-win.

So with my new favorite miner installed I moved to sell (reluctantly, but I had to get the funds for the new miners) my first BFL 10 GH miner and the two slower Rockminer 32 GH miners and replace them with however many of these Rockminer R-Box 2's as I could afford. Over the next couple of months I built up to six of them.

I set up two stacks of three each on top of our unused gas fireplace in the living room and they warmed up the place for the rest of the winter as well as providing about 650 GH/s. The electrical usage of this setup, including power supply and a small laptop running 24/7 computer was probably 800 watts or so. 

All was well until spring and the warmer temperatures outside became more frequent. Find out what happened then in the next installment of On Bitcoin Mining...

(Some Black Arrow Prospero Bitcoin miners for sale here)

On Bitcoin Mining 2

My first Bitcoin mining computer when I heard about Bitcoin and Bitcoin mining in 2014 was my PC and that is probably the case for many people when they hear about Bitcoin mining. But even in 2014 a personal computer was woefully inadequate as a Bitcoin miner and even expensive and powerful PC graphics cards were on the way out due to the rise of specialized Bitcoin mining computers known as ASICs (application-specific integrated circuits). These special mining computers could do so much more work and much faster than graphics cards or CPUs. But using my PC was just a way to see how the process worked. So I got an account at a mining pool called Bitminter and tried out their Bitcoin mining software and saw how hashing for Bitcoins worked, even at the very slow rate my computer graphics card offered. I was hooked.

My first credible Bitcoin miner was the Butterfly Labs BFL 10 GH/s ASIC miner. (GH/s is Giga hash per second or billions of hashes per second. Hashes are calculations.) It actually averaged about 11 GH/s. At the time it was $350. This was a very good entry-level USB miner and worked well with Bitminter's mining App. It does get a bit hot for its size and it is a little bit loud too but not too bad. Butterfly Labs is still selling these apparently and they can also be found on eBay for very little money. These are very good miners for hobbyists who want to see how Bitcoin mining works but there isn't much chance of making any profit. It's still a fun, low impact way to get into mining (meaning low impact on your electricity bill and not technically challenging). I actually wish I still had that first Bitcoin miner rather than selling it to reinvest in other equipment.

After using this for a couple weeks by itself, I decided I wanted to increase my hashing power. Because I was happy with the USB connectivity and the compatibility with Bitminter's App, I decided on getting a couple slightly used Butterfly Labs BFL Single SC 60 GH/s ASIC miners off of eBay. This increased my hashing power to about 120 GH/s. This increased hashing power increased the amount of Bitcoin I received. The only problem was that these miners were as loud as jet engines when they arrived. Loud and hot! There was not much chance my wife would put up with their noise in our condo for very long. I read some posts on forums online about how to deal with the noise and the heat that they produce and it was suggested to take the casing off the miners and let them work "naked". They were a little less loud like this because the inlet and outlet grills created much of the noise, but the cheap fans were also equally responsible for extra decibels. So I searched for quieter fans and found some. I swapped out the old fans with the new quieter ones and though the units ran a little hotter because the fans were slower, they were still within the safe operating temperature range of the miners. 

Summer was coming and the miners which added warmth to the house in the cool spring were adding a lot of unwanted heat as the hot days multiplied. I needed a way to get rid of the heat. What I did was to make a contraption using heating and cooling hose and other ducting accessories from Home Depot to vent the heat from the miners directly out a nearby window. Problem solved. I wish I had a picture of the setup for you but I didn't think I'd be posting about the subject in the future and didn't take any pictures of it.

Of course, I wasn't happy to stay static in terms of hashing power or equipment. I talk about my next miners in the next installment of On Bitcoin Mining.

(Some Black Arrow Prospero Bitcoin miners for sale here)