Well technically it is a violation of US electrical code to put more than a 80% continual load on a circuit (unless the circuit is dedicated = hardwired into the device).  120V * 15A * 80% = 1440W.  Peak load is 1800W but depending on wire gauge, length, etc you likely will trip the break a little below that.  Honestly something pulling over a KW of juice is an industrial piece of equipment.  In most homes about the only things that pull that much are electric stove or air conditioner both of which are on dedicated circuits.

Still if (and I am not making a prediction here) BFL did miss there power target I think scaling back the rig 20% or so would be better than trying to find higher end PSU and redlining the house wiring.   The FPGA rig ended up looking like it would pull more than 1600W so they split those orders into two "minirigs".  

Personally I like the idea of smaller units rackmounted anyways.  With the "upgrade" Avalon would be ~88GH for ~ 530W.  Standard datacenter rack could still hold 880 GH/s and use ~5.3KW or power.   A locking L6-30R outlet on a 240V, 30A circuit and a PDU would allow a safe, neat, and efficient setup while still being electrical code compliant.

I remember when predictions of Bitcoin going under $1 were all the rage.  $8... meh.  I guess that means the bear have increased their valuation by 700%.

I wonder if in a couple years we will see some brave predictions about how Bitcoin will will be under $50 by next year.

Interesting on the 77% stats for BTCJam.  I wonder how many lenders realize that if the successful repayment rate is 77% and the average interest rate is less than 29.9% then it is a capital sink.  Meaning that collectively the repayments are less then the amount lent.

Wonder if the JTCJam operators are willing to publish a ROIC% for the whole site.  My guess is -30% annualized.

The attacker can then "slow down" allow difficulty to fall and mine again but even that won't be necessary.  Remember what makes the chain the "longest" the total combined difficulty.  So a very far miner will build a longer chain eventually.  It might have a lower block height but it will be "longer".

I don't know if there is a stat for the total combined blockchain difficulty (sum of all difficulties of all blocks in the blockchain) but I would guestimate it at ~250 billion combined difficulty (roughly 100,000 blocks in last 2 years @ avg difficult of 2 million and a much smaller amount prior to that).

Still it will require a lot of hashpower, far more than 51%.  Also as time goes on the blockchain contains more and more "stored difficulty" especially years and years of high difficulty (ASIC generated) blocks the amount of hashpower required to rewrite a significant portion of the blockchain becomes prohibitive.

Also I would point out the reference client (and many others) use checkpointing which means that one can't rewrite the blockchain prior to the last checkpoint even with infinite amount of hashpower.

51% attack is a credible threat but much like the attack on napster spawned better protected p2p networks and eventually bittorrent a 51% attack would simply pawn new cryptocurrencies hardened against brute force attacks.  

No.  If there is a breaking change then BitcoinA won't see blocks from BitcoinB as valid and vice versa.  They both would exist independently until one chain is completely abandoned (a 100% consensus event). 

You can't force a change.  All you can do is fork the network.  If enough people join your fork then it may become dominant.  If only a few people remain on the original fork it may eventually become unknown to the masses (as other obsolete protocols have become).  As long as a single copy of the current software and blockchain exist the current fork (Bitcoin as it is today) will always exist.  As long a single node is actively mining the network will remain.

So all of your possible choices are incorrect and impossible.  None of them can force a change.  The only thing which would prevent a fork is complete unanimous consent and action by all users.  Not 99.999999999999999% but exactly 100% (past, current, and future).  All users agree and update their nodes, then a change will occurs without a fork.  Baring that near impossibility to make a breaking change to the protocol will cause a fork.

We have been looking.  It is difficult to finds irreversible funding methods which are accessible to the general public.  Those that do exist tend to have large barriers to entry.

FYPFY.

Asked and answered many times.  Use search function.

Simple version it isn't an issue.  Bitcoin is highly divisible and with a small protocol change (if necessary) can be even more divisible.

No reward needed.  It helps me to understand it better by explaining it to others.

Well the nice things is there is an economic cost to the miner.  If the miner starts to notice their orphan rate skyrocket then they may wish to investigate why their blocks are taking so long.  Not sure how much it would increase the orphan rate but I would imagine a 3 minute (or even 30 second) verification time would destroy the pools competitiveness.  Earn a lot of fees and lose the block worth 25 BTC isn't really worth it.  When miners are willing to change pools over a 1% difference in orphan rates it shows how economically sensitive they are to anything which disrupts earnings.

Correct. Although it is probably better to just think of the coinbase tx as another tx.  

When a node receives a new transaction it:
a) verifies the inputs haven't been previously spent
b) verifies the signature on the transaction is valid (signed by the private key(s) of the inputs)
c) verifies this transaction isn't already included in a block.

All (full) nodes have a complete copy of the blockchain and thus all confirmed transactions.  So it is important for a node to have an accurate record of all (known) unconfirmed transactions.  This is called the memory pool.

When a node validates a new transaction it adds it to the memory pool.
When a block is validated the block is added to the blockchain and the transactions in the block are removed from the memory pool.
When a block is orphaned the transactions in the block are added to the memory pool (many or all may be removed again if they replacing block also contains them).

This way all nodes have a set of transactions they are aware of which haven't yet been included in a block as well as all known blocks and the chain which is currently the "longest". 

No.  That is intentional.  Miners are free to choose which tx then want to include in any particular block.  Miners can't force users to include a fee but they can choose to exclude low paying or non-paying transactions.  Users on the other hand aren't guaranteed inclusion in the block but can't be forced to include a fee.  The mining "economy" will meet in the middle.  Currently subsidies make the overwhelming portion of miner compensation but overtime fees will become more important.  

30%

Not exactly sure how the OP will sell 1 BTC for $25 which nets him $17.50 (before fraud losses, chargebacks, and profit margin) ...

Simple version:
It murders GPU miners in their sleep.

You can't buy one today.  Batch 1 already sold out.

Batch 2 will pre-order "soon" (tomorrow?).  $1499 for 66GH/s (68GH/s observed in testing).  Payment in BTC only.  No cancellations.  Expected shipping in March.

http://launch.avalon-asics.com/

I rarely agree with gweedo but he is right.  Harsh but right.

ASICs don't suddenly render the current pools obsolete.  Some of the larger miners will solo and the the smaller ASIC players will continue to use pools.  In time 60GH/s will be like 1 GH/s now.  The numbers will go up but everything will reamain the same.

Making a "new" mining pool today and trying to get people excited would be like pitching an idea to make a new "geocities" in 2013.  Meh.  Now don't let this crush your dreams but try to think creatively.  A "new" pool is about the last thing Bitcoin needs right now.  How about making a storefront site (think amazon stores) which allows people to create a webstore and accept Bitcoins easily.  By easily I mean not a line of programming.  Everything through a web front end.  Setup items, categories, products, photos, prices.  Allow clients to price in static BTC or static USD where price in BTC floats.  If you want to get real ambitious look to integreate stripe and allow merchants to accept both BTC and CC on the same easy storefront.

Now that would get me excited (if I didn't have a million things to do already).  Another pool?  How pedestrian.   It was interesting the first 150 times.

Yeah looking at the post 2 up that does make it tough.  My guess is that the bankrupt company isn't trying to pull a scam.  They likely wouldn't remove the toner until it was used completed and then probably wouldn't hang on to it.  If it was a printer cart I would say check the printer to see if it has a MICR toner cart installed.  That would indicate they probably started printing checks at one time and the "spare" toner is probably the original and partially used.

Being a copier that doesn't apply so my guess is it is new.  No real way to tell, not without access to a compatible copier.  The higher end toner carts have microchip so loading it into the correct copier should show the number of copies made (somewhere in the setup menus ).

BTW: My first job in IT was tech support for Cannon. 

If it is using the word Canon on it and doesn't come sealed in a Canon retail box with hologram it is at best a fake and at worst a used fake.

Note I got no problem with off brand toner but Canon is a trademark of Canon so there is an honest off brand manufacturer calling their product "Canon L50 compatible" and then there are the dishonest ones trying to pass theirs off as a genuine Canon (or HP or xyz) part.  If you can't trust them enough to be honest with the labelling who knows what else they are faking. I mean it is very easy to design a toner cartridge which has 1/4th the toner (and more plastic makes it weight about right) so even new it could produce less pages then a used one would.

I'll gladly take 1/1000th of a ton of gold.

dust got it right.  If it was exactly the same chip one would expect closer to 2x to 3x better efficiency.  A lot will depends on the exact design.  Personally I think Avalon went the right route.  Any ASIC is far superior to GPU so use 110nm, get a simple working design out the door.  A couple million in sales later you got plenty of money to do an improved design maybe tweak out 50% to 100% improvement in efficiency at the same 110nm, and THEN make a move to smaller process.  If your competitors are crushing you then you can either jump to 65nm or take a gamble on more efficient design AND a jump to 65nm on the same chip.  Get the most out of your resources and leave yourself options to improve.  Note this strategy is called tick-tock and is used by Intel.  Intel used it to good effect to utterly destroy AMD. 

Tick - do a die shrink
Tock - improve the efficiency (2nd gen design on same die size).

For the record I don't think BFL is a "scam" but my guess is 1000 MH/J is the high end of their range.  With real world inefficiencies, power consumption rising due to ambient temps, power supply inefficiency, and simple variance in chip yields I think they will underperform that number.  Note probably not 500MH/J vs 1000 MH/J but maybe 10% to 20% below.

Note the following is a totally hypothetical example made up completely for my amusement.

Tick - 110nm Avalon (160 MH/J)
Tock - 110nm Improved Avalon (280 MH/J)
Tick - 65nm XXXX (560 MH/J)  <- improved avalon design die shrinked to 65nm
Tock - 65nm XXX (800 MH/J)  

Its over $50 per BTC so I think the markup is "sufficient".