What to know about the Bitcoin 0.8.6 update

The official Bitcoin 0.8.6 update was released this week, and some of the tweaks include bug fixes and updated limits on block sizes.

The block-size limit is the biggest change going forward. The update changed the maximum size of free transactions from 10,000 bytes to just 1,000. Now, it is possible to have 27 free transactions on a block, a nine-fold increase over the last update.

The default block size for miners was also increased from 300,000 bytes to 350,000 bytes. High-priority transactions have been allotted 30,000 bytes, as well.

Also, the minimum output requirement of 0.01 BTC has been done away with altogether, reflecting the increased value of the currency.

A few bugs have been fixed in this update, too. The issues that were corrupting the block chain in OSX 10.8 and 10.9 have been fixed, and developers have introduced alternative fsync methods.

Developers warn that some users on 32-bit machines could run out of virtual memory while the update syncs. Update 0.9.0 will feature native 64-bit support. In the meantime, here is how to run the newest update:

  • Shut down any older versions, and wait for it to shut down completely.
  • Run the installer if you have Windows, or just copy over /Applications/Bitcoin-QT on Mac and bitcoind/bitcoin-qt on Linux.
  • Be patient, especially if updating from 0.7.2 or earlier, as blockchain files will be re-indexed, and this process could take a few hours, depending on your machine’s speed.