<p>Blocks are downloaded from other nodes in Bitcoin's P2P network using a custom wire protocol. For the initial synch you can imagine it as a torrent with 5000 seeders, though the Bitcoin P2P protocol is more specialised and efficient for this task than BitTorrent. </p>

<p>The bottleneck is almost always CPU load on validation, rather than download speed. </p>

CC BY-SA 3.0
2015-11-23T07:38:50.213Z
2015-11-23T07:38:50.213Z
Claris
<p>Is it p2p through BitTorrent protocol? Is it through a central server?</p>

<synchronization>
When I'm downloading the blockchain for the first time, from whom am I downloading it from?
davidhwang
# When I'm downloading the blockchain for the first time, from whom am I downloading it from?

(Asked by: username_0 on 2015-11-23)

Is it p2p through BitTorrent protocol? Is it through a central server?

**Tags:** synchronization


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## 1 answers

### Answer by username_1 on 2015-11-23. Score: 6 | Accepted answer

Blocks are downloaded from other nodes in Bitcoin's P2P network using a custom wire protocol. For the initial synch you can imagine it as a torrent with 5000 seeders, though the Bitcoin P2P protocol is more specialised and efficient for this task than BitTorrent.

The bottleneck is almost always CPU load on validation, rather than download speed.


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