Ok, why are my transactions listed as "low priority", when identical to others?

[djproject]

For example, I get a 258 byte "low priority" transaction when paying .0005 as a fee, even though another transaction which is also 258 bytes and also pays .0005 as a fee, is not "low priority".  What could be the reason?  (These measurements based on the Bitcoin Charts)

[1714116329]

1714116329

[1714116329]

1714116329

[1714116329]

1714116329

[1714116329]

1714116329

[1714116329]

1714116329

[1714116329]

1714116329

[grue]

coin age

/thread

[djproject]

My coins haven't been touched for a very long time.  Do older coins = lower priority?  That wouldn't make much sense

[payb.tc]

could also be transaction age.

if you just initiated a transaction and then immediately looked at bitcoin charts, yours would be the newest out of all the 258 byte transactions.

[djproject]

Thanks for the help.  So in the future, what's a guy gotta do to secure a modest transaction and not have it take forever?  It seems like my transaction with a fee is significantly lower priority than a lot of transactions without a fee, even ones which are 10 times more bytes than mine and about the same age

[koin]

what's a guy gotta do to secure a modest transaction and not have it take forever?

just to make sure you are not misunderstanding anything.  your transaction with a non-zero fee will likely make it into the next block regardless of what it shows as priority.  even without a fee it would probably get included.  

the next block happens when the next block happens, regardless of your transaction's priority.

[payb.tc]

yep, back when i was very new to bitcoin, i set my transaction fee to 0.02 because i thought that would make them go faster than 0.01.

whoops, turns out it didn't exactly work like that

[deepceleron]

The priority doesn't change based on how deep in the queue it is. The priority number is based on a simple formula.
Unless the payment has a decent fee included, priority under 57,600,000 is low priority. The mainline Bitcoin client will prompt you to include a fee in low priority transactions to ensure they are processed, but the .0005 minimum fee is not enough to get most bumped up (although with any fee above that they should be quickly included in a block).

https://en.bitcoin.it/wiki/Transaction_fees

"priority = sum(input_value_in_base_units * input_age)/size_in_bytes"

Since when you send coins, the entire address balance is usually sent (with change sent back to you at a new address), this is typical:

priority = ((BTC address balance*100000000) * number of confirmations (weighted over all coins) / size of transaction message in bytes, usually around 300)

For example, send 1 BTC that has been in your wallet for 100 confirmations, in a 300 byte transaction:
100,000,000 * 100 / 300 = priority 33,333,333 = low priority

Priority is only a problem if you send with a 0 fee; see for example the 1VayNert withdraws from the Deepbit mining pool to it's clients: while Deepbit is happy to keep all the transaction fees of blocks they mine for themselves, they don't pay anything back out when sending you a payment, so it may be delayed for hours.