Last week somebody was saying they thought bitcoin is the "most efficient" way to pay, so I crunched some numbers to find out. Summary: it is not.

Currently 262 Terahash/s=262E12 hash/s
Most efficient bitfury hardware gets 705E6 hash/J, or 1.42E-9 J/hash ==>Note I'm being as conservative as possible here, in BTC's favor

So total network power consumption is at least (1.42E-9 J/hash)*(262E12 hash/s)=372040 J/s = 372 kW. Like I said, this is the most efficient scenario, with little room to improve with new mining hardware in the future. A year ago it was far, far worse.

36944 bitcoins change hands/hour, on average.
(3600 seconds * 372040 J/s)/($100/btc*36944 btc/hour)=362 J/$ processed.

Now let's compare to Visa. Visa processes avg $6.7T/year= 6.7E12 $/y = 212456 $/second. If Visa consumed as much power as bitcoin, that would be (362 J/$)*(212456 $/s)= 76.9 MW of power.

Visa has 2 datacenters in N America, consuming about 25MW each. And that includes stuff like AC, that I didn't even consider for bitcoin. So Visa actually uses far less energy/$ than bitcoin. And bitcoin is getting less efficient every day as the hash rate grows.
http://usatoday30.usatoday.com/tech/news/story/2012-03-25/visa-data-center/53774904/1

Discuss.

It's interesting to watch the dirty laundry come out... BFL always gets it worst cause they're the clear leader.

An inside story about somebody who hates BFL -- this is fizzisist. He's pretty well-respected around here, at this point. He has been a strong BFL opponent from the beginning (for obvious $ reasons). When I started the X6500 with Li and fpgaminer, I invited fizzisist onboard. From my dealings with him, the guy came off as a real scumbag. The backstabbings came quickly. At one point he tried to drop the heatsinks off our boards to gain a few bucks profit off each, when heatsinks had clearly been promised. Anyways, I soon found myself on the outside of the group I had started. And the X6500 launch was delayed for a few months due to incompetence and bickering...

What's the moral of the story? Take your pick:
-Nothing whatsoever
-A public persona isn't always what it seems
-Scumbags can still sell good hardware
-It's always interesting to watch the pot call the kettle black.

All of that being said, my opinion is that BFL is probably safe to buy from. Personal identities are known, they've been visited in person, and they have a track record that's as good as any hardware maker (except maybe Ztex, his rep seems to be flawless). Clearly they're going to get rich either way... why wouldn't they choose the route that doesn't involve jailtime?

It's nice that you aren't charging an arm and a leg for small order quantities

With the massive amounts of money that are going into mining hardware right now, I wouldn't touch it with a 10-foot pole. If you do, BFL is the most profitable option by a wide margin.

I think it's time somebody gave BFL a pat on the back. It's impressive that they put together a complete package for $600. Custom processors, custom enclosure, custom heatsink... that's a lot of engineering work. It sounds like everybody else is gonna have a very hard time matching the new BFL processors.

This is phenomenal that you could get the cost down so low. My only complaint was going to be the JTAG interface. But, since you've accounted for daisy-chaining 6 of them... that complaint is gone. Hopefully your JTAG signal integrity holds up from daisy-chaining 6 boards. It's touchy.

Give the bitcoin community some time to warm up to your idea. There've been enough scams going around, so it's no surprise they don't jump on the bandwagon right away.

About fpgaminer's open-source code and ztex's "borrowing" of it-- the issue wasn't that ztex borrowed a few bits and pieces. It is open-source after all. I think the issue was lack of acknowledgement.

Me being around wouldn't have changed things from here on out. I just help with design and PR-- now we (or they) are in the assembly stage.

Well, with a little luck and lots of hard work from the remaining team members, you will still probably get your boards in early November. I was pushing them too hard to cut costs and make progress... and they didn't like that very much

I'm going to start this deal up again-- now paying .04 BTC for joining up!

What's up with those squiggly traces, ngzhang? Never seen that before

I just want to announce to everybody that I'm leaving this FPGA project. This is due to disagreements over project direction and pace.

Well, good news. The prototype PCBs were finally ordered by Li yesterday. Here's a little glimpse of what the board will look like...


We've added a few features... like the barrel connector, some fuses, and reverse polarity protection. Also small changes to the text, etc. But it will give you a good idea. It's going to be very cool-looking, especially with the heatsinks (which are going to be passive).

The board size is ~100 x 80mm.

Hobbyist or not, which one has made more money? OK, I don't know. They've both probably made a lot.

With these low prices, which one stands to make more in the future?

The price is only gonna go so low. I mean, there are still a lot of people who are interested in and use bitcoin. It's perfect for Craig's List-style trading. There's no way it's going under $2.

Well, let the real commerce begin. Can anybody make me a deal on some 26 x 1.5 bicycle inner tubes? I want about 10, if the price is right.

Hey kazoo,

Thanks for the order! first of all. We haven't released any schematics yet. I don't imagine we will anytime soon, because FPGA's are turning into a hot field. Wouldn't want to give away our secret sauce. But, if you send me a PM, I'll answer almost any hardware question you want.

FPGA costs have come down like crazy in the past few months. Our dual boards do 200 Mhash/s for $610. If we are able to hit an order size of 1000, cost will come down by $50 or so. If we get the automatic overclocking software up and running, then it will be something like 280 Mhash for $550. At 15 watts or less. Sounds competitive to me.

My opinion is, we aren't far from seeing FPGA order sizes hitting 1000.

There's an interesting discussion going on about FPGA's here:
https://bitcointalk.org/index.php?topic=40865.20

Foul language warning!   

Pretty well, Karmicads. Today we talked about how we're going to protect the circuit from overcurrent. We might also be adding overvoltage protection. Small details basically. I'm pushing hard to send the board design out on Sunday afternoon, to get our prototype made.

I think it's fitting that molecular is about to become a Hero Member.   

He's right about the variation on hash rate from our boards. They are pretty much hard-wired to run at 100 MHz right now, doing one hash per cycle. Any variation on that is due to latency communicating with the pool or something like that.

Here's a little cost analysis of our board. You guys will find this interesting, I think. Basically it shows that the preorders were enough to "get us over the hump", where the price is really steep. From here on out, there's little gain to be had, until we get to 1,000 units.


It's a good thing we got at least 50 orders, otherwise I don't think we could have delivered for under $620. Like fizzisist was saying, all those little taxes, shipping, and Paypal fees really add up.