How many did you buy? Could I still order some from you?

Given the drop in price of BTC, and of the Erupters themselves, I would definitely go ahead. Maybe even get 6 instead of 5 for 2.0GH/s (Assuming the hub power supply can deliver 3A reliably -- I have not tested this)

That's just me though. You have to make the decision for yourself. You would be getting a much better deal than I did.

Hello,

Can someone explain to me how to sign a message in Armory? I want to prove that I own a particular address. I'm trying to use the Message Signing tool, but it's either crashing or not generating a signature.

Thanks for the encouragement and support, guys! I'll try to keep this thread updated

Here's an update now:

• I have mined my first bitcoin, and used it to purchase a Certificate of Deposit.
• It took 25 days to generate 1 BTC.
• The rig is completely stable.
• The offline laptop securely signed the outgoing transactions as intended.
• I had to create two accounts to buy the CD: one at coinlenders.com, and one at Inputs.io
• The inputs.io web wallet confirmed the deposit in about 5 minutes, and transfer to coinlenders was instant.
• The CD will mature in 30 days @ 25.5% APR.

I'm aware that there is a risk associated with lending my BTC, but that's all part of the experiment.

It's also worth mentioning that the price of BTC has crashed. I bought at approx AUD$135, and now it's about AUD$85.

The rig has now accrued a current uptime of over a week, and has generated about 0.7 BTC in total. The fan has resolved the stability issues.

I appreciate your candor, and will take your advice. Yes, I got swept up in the whole "cryptocurrency is super-cool" bubble, and didn't fully understand everything before diving in. Rising difficulty is killing me here, and the ASICs were overpriced.

What do you suggest I do? Keep mining and hope the price of BTC will go up, or sell the damn things on eBay before they becomes worthless?

My energy provider is ActewAGL, and my bill has 2 components: a flat fee of AUD$0.605 per day, plus AUD$0.179 per kWh. The rig draws 20W at most. So to run for thirty days is 30 days * 24 hours * 0.020kW * AUD$0.179 = AUD$2.58

I had stability issues when running USB eruptors without a fan: hashrate in cgminer started to drop after a few days. The arctic breeze usb fan is perfect for cooling the block eruptors, and it does lower HW error rate by about 0.2%

How much current does your power adapter deliver? The USB eruptors require 500mA each. The DUB-H7 can deliver 3A, which is 5 eruptors and 1 fan, or 6 eruptors.

What's your HW error % rate? Divide HW by A to get it. Mine is 0.8%.

EDIT: You might need to calculate it individually because you have other hardware besides the AMUs.

Found a bug in 3.2.1: after several days of running, the output became all HW errors. I didn't manage to get a screenshot of it because it went back to normal after looking at the Pools settings, but could it be an integer overflow somewhere in the code? The hardware was still functioning normally.

Hey, buddy! We've got a similar setup! What's your guess about the ROI of the AMUs?

BTW, what sort of cooling are you using, if any?

In that case I'm getting about 0.8% error with cooling. Without cooling I'm getting 1.0%

However, without cooling, my hashrate starts to drop after a couple of days. The fan seems to fix this.

Welcome!

Your first decision to make is what platform you are going to use. As far as I know, there are 3 major options: GPU (based on your graphics card), FPGA (field-programmable gate array), and ASIC (application-specific integrated circuit). They all have their strengths and weaknesses, including cost, hashrate, power consumption, and availability. I personally think the custom USB ASIC devices are the way to go. The Butterfly Labs Jalapeno seems to be the best device at the moment -- but they are scarce. I personally went with the USB Block Eruptor, but I overpaid @ BTC 2.6 each for five.

The simplest thing to do would be to run guiminer and mine from your graphics card. No additional hardware needed.

If you want to try custom hardware, the easiest thing would be to just stick one Block Eruptor into a spare USB port and watch the Satoshis flow in.

If you want a more robust setup, you could invest in a Raspberry Pi (it's basically a tiny computer that can run Linux) and a powered USB hub to drive numerous Block Eruptors. Just be aware that it could take a year or more to get your investment back -- and who knows what the price of BTC will be then.

Just make sure you know what you're getting into, and you'll have fun.  

I had a similar idea based on a Spartan 3E FPGA, but I determined that it's just not worth it. If you want to experiment with mining, do it on your GPU.

What's the formula to calculate HW error % rate? HW divided by A?

Here's what I've learned from my case study: rising difficulty and high hardware costs make USB Block Eruptors less effective than I'd hoped. Mining is only worth it if you think the price of BTC will go up again.

Actually, scratch what I said. I haven't run the rig long enough to see if the cooling affects the HW error rate this much. Watch this space.

You are absolutely correct that this project will succeed or fail depending on the price of BTC.

I've come to realise that I underestimated the challenge posed by rising difficulty. Also, the price of the hardware was rather high. However, BTC interest rates are also high -- around 25% per annum -- so I can offset these losses by purchasing Certificates of Deposit. The plan is to keep the currency in Bitcoins, NOT cash out to fiat.