Topic: A couple questions (Read 532 times)

It will not be a problem to have them in the same wallet with "big coins".  The coin selection algorithm attempts to minimize tx size.

Of course if you transfer them to a new wallet (or address or same address) you will consolidate them into a single output worth 5 mBTC but it will be a ~3KB tx and thus 0.3 mBTC in fees.  It won't be free but that is the cost of small inputs and now you have a single 5 mBTC output.  Honestly I would't worry about it much but if you want to that is always an option.  

In general if you can control it (a cashout from a pool or exchange) always try to keep your outputs as large as possible.  5 mBTC in 1 transaction is going to be cheaper to use than 5 mBTC in 15 transactions (or 150).

I have total 5 mBTC with 15 transactions, is it big enough to not mix this wallet with my biggie BTC that I'll be buying in next few days

Potentially.  Each time you receive "coins" it is a single discrete output.  Those outputs of are used as inputs for new transactions.  On average each input is roughly 120 150 bytes and the network charges a fee of 0.1 mBTC per KB making the cost of spending a single input ~0.015 mBTC.  Inputs with roughly this value (even say 3x or 4x higher) are going to end up with fees that are either a large fraction of the amount sent or more than the amount sent.

Since you indicated roughly 200 tx and 0.1 BTC total, in theory a tx with 200 inputs and a single output (consolidate all 200 outputs into 1 new output) would be ~30KB and being low priority would require 3mBTC in fees.  That isn't too bad since you state the the total is 100 mBTC (0.1 BTC).  You are looking at ~ 3% in fees to consolidate that 100 mBTC in 200 outputs into a single 97 mBTC output.

So while your tx may be "dusty" they are on the high side of dust (pebbles?) and thus aren't completely worthless.  There is a lot of dust that is 10x even 100x smaller and the value of those rapidly approaches zero (at current exchange rate). If you had 2,000 inputs totaling 1 mBTC well that would be worthless, you couldn't spend them without fees being worth more than the value you are trying to spend (at least until the exchange rate goes up a lot).

There is no issue with having dust in your wallet.  The coin selection algorithm attempts to minimize tx size and thus will exclude dust unless it has no choice.  

This could be improved by if someone wanted to do some work making the coin selection algorithm smarter.  One could including one or two dust inputs in each tx (just enough to ensure the tx doesn't go over the next KB limit).  Since Bitcoin fees are per kb, a 300 byte and 1000 byte tx pay the same fee.  No reason not to spend a couple dust outputs in every transaction to "burn em up".  With Pay To PubKeyHash involving compressed keys ("normal Bitcoin transactions") the inputs are ~ 150 bytes each and the outputs are relatively tiny at ~15 bytes each.  Using a single input, an two outputs (receiver + change) that makes a tx ~180 bytes.  There is enough "room" to cram in 3 or 4 dust inputs into the tx without the fee going up. 

Another way to look at it is the current "min mandatory fee" on low priority tx (high priority tx have no mandatory fee) is 0.1 mBTC.  That makes the cost of spending one input about 0.02 mBTC however using the method above or by making the tx high priority and paying it back to yourself you likely could combine the "larger dust" (pebbles) at a much lower cost if you were willing to wait.  Simply combine one large/old input with a lot of dust and attach a non zero but less than 0.1 mBTC per KB fee to the transaction.  If you are willing to wait hours (or maybe days) eventually a miner will pick it up.  The key is to ensure the tx is high priority so it will be relayed with no (or "too low") of a fee.

Of course doing all this manually would be tedious, likely netting you a tiny fraction of min wage in "dust recovery" but there is no reason clients couldn't become "smarter".

Indeed, this is good advice. This was actually one of the useful things about inputs.io...you could send endless dust and the output transaction fees were always the same.

This is a perfect example of how Bitcoin isn't backed by nothing, as some claim, it is backed by the transaction cost (computing power + electricity).

All you can do when collecting Bitcoin dust is wait for the price to rise to make it viable to spend.

Never mix dust with you main Bitcoin wallet keep it in a separate wallet.

yes they are taking too much fees for these small transactions I have also expereince like this after this I never do work on any faucet its waste of time and nothing more

Hello, I'm fairly new to this but am approaching 0.1 BTC from faucets, PTC, and a few "work for bitcoin" sites. I have a couple questions.

1. When I view my wallet on blockchain.info, it says I have a very large number of unspent outputs, and asks me to consolidate them. Could someone explain this - does this refer to all the small deposits that have been made into my wallet (about 200 transactions), and that there are too many of them? Do I fix this by sending my entire balance to a new wallet that I create?

2. When sending BTC to another wallet, either myself or someone else's, will there be a sizeable fee, since I have accumulated only about 0.1 BTC over the course of 200 transactions? I'm guessing all those transactions caused some data size buildup. I could use an explanation of what to expect here. When I send my balance to another wallet, will I end up having to pay a greater amount in fees than I actually have in my wallet?

Thank you!