Topic: 1GH/s, 20w, $700 (was $500) — Butterflylabs, is it for real? (Part 2) - page 5. (Read 146880 times)

hang in there.. its only 4-6 weeks away!

UPDATE: I asked Sunny when I could expect my shipment and in less than 15 minutes received a response back that since I am in Asia, I should expect it mid-March. I hope Vladimir gets a chance to try it out before I get mine. Worst case scenario, I'll do some basic review photography etc in Korea and let Vlad do the specs.

Nope.

Each bitcoind is passing out work for hashing a different 80 byte header.

The header is (bytes):
version(4), previous(32),merklroot(32),time(4),difficulty(4),nonce(4)
version,previous,difficulty are all the same for everyone.
time is the same for each person who happens to have the same second in their header
nonce is what you check 2^32 different values for (~4billion) for each getwork() request

So that leaves merklroot.
Every bitcoind will have a different merklroot because every bitcoind has it's own coinbase transaction with their own payment address.

So on a single pool (one bitcoind) everyone is working on hashing the same data but that is also resolved 2 ways:
Firstly of course with time each worker asks for work - some will be the same but of course not everyone will be.
For the ones that are the same there is a secondary way to have a different 80 bytes: by having a different merklroot:
The coinbase transaction can have any random string in the actual coinbase field - so they can resolve passing out the same work by giving each worker that asks for work within the same second, a different coinbase content.

So yeah basically what it all means is that EVERYONE who is hashing is actually hashing something different (unless the pool software is crap - then some people on the same pool may be hashing the same thing)
and everyone is trying to get an answer that is less than difficulty - but no two answers will likely EVER be exactly the same either.

Off-topic - how to use 100W on Icarus
https://bitcointalksearch.org/topic/m.756349

There is no such thing as 'working together' with simple brute-forcing. Everyone in the whole network is biting at the same slice of pie. Probability is the only thing preventing massive repetition of work.

We've already seen 813MH/s anyway - https://bitcointalksearch.org/topic/m.748164
so obviously there was something that made this one lower ...

Somewhat disappointing.  I figured the first SNAFU with promised specs would teach them to underpromise this time.  

Didn't he have a "winblows crapdate" restart during that so the share count will be low? ...

I just ran some numbers for Inaba's Single @ https://eclipsemc.com/mw.php?key=196e69b1afe10927460b22a8de1c0d:

3:23pm CST: 65612 shares
12:08am CST: 70949 shares (8h45m later)

So the average hashrate during that 8h45m period was:

70949-65612 = 5337 shares in 31500 seconds (8h45m)
5337 shares * 2^32 hashes/share is 2.29e13 hashes
2.29e13 hashes / 31500s = 727Mhps

Not too bad, but still 13% lower than the advertised specs of 832Mhps. 

Nope not an issue.

I'm wondering if the holdup is related to having problems with more than one box hooked up? Maybe they haven't gotten multiples working together yet? I'm wondering how it would work even. Would each one be given a slice of the pie to chew on or ?

Great question. We've got 13 BTC for a tracking number and an unboxing video! If anyone else wants to add to the bounty, PM me.

I made two orders for singles, so one order will be  late and one will be on time. BFL is starting to catch up.

4-6 weeks for the singles? There's a shocker.

Most powersupplies are 120-240V.  If it can run on 120V @ 20A circuit it would work fine on a 240V @ 10A circuit too.

I doubt the powerspecs on the rigbox though.  Single only gets 10MH/W.  I wonder if the rigbox spec is based on the same "simulation" that caused BFL to advertise the single @ an insane 50M/W

That's great for all of you in the USA and in Japan. How about the rest of the world which uses 220-240V?

I was gonna say that it doesn't really matter coz FPGA's don't use much power so you're not really ripping them off much ... then I realised I was in the wrong thread

The ports are probably blocked... not that I've tried

Naw you just get sent to rehab to face your mining addiction!

And get fired when the IT guy notices your computer never stops talking...

Just got a email from BFL, looks like I will see a rig box by the end of April and a couple more weeks from now for the singles!!

"your units will not have the fan underneath.  You'll be getting rev 2 units which have a wider temperature tolerance."

has anyone seen a pic of Rev 2?

I would like to see them sooner than later, but I will settle for better late than never.  


I'm still wondering how the rig box will use half the power Per Mh as the Singles. I asked BFL what they expected it to require for a circuit, and they said a single phase 120v 20amp... that's not much... I figured for sure a 30amp..

I had a cool idea, someone should make a FPGA miner that fits into a 3.5 drive bay...  then you could hide a few in your system at work hehehe