New users are often frustrated at the time required for a new Bitcoin installation to update before it becomes useable. This post outlines a faster way to get up and going if you are experiencing longer-than-expected delays.
When you install and run the Bitcoin client software for the first time, Bitcoin must download the complete Bitcoin blockchain from other Bitcoin clients sequentially in pieces starting at block 1. The blockchain is a record of all transactions that have ever taken place, and you must have the complete record before you are able to see your own balance and send payments. The transactions are grouped into cryptographically secure transaction blocks that were created about every 10 minutes since Bitcoin was launched in 2009. As of Dec 2013, there are over 270,000 blocks, over 12GB that need to download over the p2p network, which can take many hours or even days. The download speed is also limited by processing power, as your CPU must verify transaction signatures and the validity of past payments, and your hard drive must keep up with the intensive I/O access building the database where Bitcoin stores transaction information.
Bitcoin-qt 0.5.x-0.8.x screenshot:
In the screenshot above, we can see by hovering over the network icon that this Bitcoin-Qt client has 71 network connections to other users running Bitcoin. The maximum if you are using an Internet router appliance or NAT without port forwarding will be eight connections. We can also see Bitcoin has downloaded all transaction blocks up to block 164944. If a transaction was sent to you now, it would be included in a future block - you would need to wait until that transaction is added to the blockchain and downloaded by your client in order to see an updated balance. There is one payment to this Bitcoin wallet in the screenshot, received around block 150000 - if Bitcoin had only downloaded blocks up to 100000, this transaction wouldn't appear in the client at all.
Your client must be making some connections, and should start downloading blocks within a minute of starting. If this does not happen at all, you need to remedy this problem; typically it is a firewall or antivirus program blocking Bitcoin's connection to the Internet, or something is misconfigured on your network. If you are limited to eight connections, you can improve this by forwarding port 8333 in your Internet router to the computer running Bitcoin. If your Bitcoin is well connected on high-speed Internet and has a fast CPU and SSD, a new installation can be ready in as few as four hours, but may take much longer if conditions are not optimal.
Fortunately, there is a method that is often faster.
A blockchain import feature was added to Bitcoin version 0.7.1+ to "bootstrap" or import an external blockchain file, while still performing a full validation on the Bitcoin blocks being added. Whenever Bitcoin is started, it searches the data directory for a file "bootstrap.dat", and if this is present, it will import all new blockchain blocks contained in the file. This procedure still requires the same CPU and disk resources, but can be faster if network speed through the p2p network is the limiting factor (which is often the case, Bitcoin only attempts connections to one other peer at a time to download blocks).
A torrent is maintained that contains blocks up to the last hard-coded checkpoint block in the client (currently block 250000, 9.1GB of blocks). Only blocks after this checkpoint will need to download off the peer-to-peer network.
Download the torrent with this link:
http://sourceforge.net/projects/bitcoin/files/Bitcoin/blockchain/bootstrap.dat.torrent/downloadMore torrent instructions and links on this thread:
https://bitcointalk.org/index.php?topic=145386.0After completing the torrent download, you will need to copy the file bootstrap.dat to your
Bitcoin data directory. To locate the default Bitcoin data directory on your OS, follow instructions on
this link. When you restart Bitcoin, you should see the import progress dialog.
(
Edit Apr 2013 - removed all direct download information except bootstrap torrent, Dec 2013, update blockchain and torrent sizes.)
