Post
Topic
Board Bitcoin Discussion
Re: [ANN] Bitcoin blockchain data torrent
by
washuu
on 14/01/2016, 11:00:52 UTC
With new versions, the torrent is ABSOLUTELY NOT FASTER. It is faster and easier to allow Bitcoin Core to sync normally, no need to download a massive file, and the sync is faster due to headers-first synchronization.


Let me share my story.

I have a small NAS, used also as set-top box to my TV. It runs debian. I decided to give the Bitcoin a try, and set up a node - I have plenty of space there, and this box is used sporadically.

I downloaded fresh version of Bitcoin (at that moment, 0.11.02), and started downloading the blocks normally. I have a decent speed to the internet.

I took over a month to download the whole blockchain, and I have logs to prove it. I have monitored its progress - bitcoind used just a small bandwith, but always 100% of my CPU, on the NAS. It os not very powerful CPU, I admit, so I wasn't surprised. It was the computation that caused the blockchain to load slowly.

When it finished, and started running "normally", the CPU consumption was about 20-40%. It was quite expected. But I decided to give the torrent a try, just for sake of comparison.

The torrent I took from the above linked thread. The torrent downloaded on the same box, with the same CPU and network,  in about 7 hours. Then, I needed to download missing blocks - it took about 36 hours. In total - 42 hours.

In both cases the blockchain is about 62 GB big. The MD5 of the files are different, though.

Now my points:

 - there are computers with slower CPU. Keep this in mind. My case was extreme, but it's just proof, that CPU is also very important during downloading the blockchain, and people having problems with slow downloads perhaps have probelem with CPU, not network.
 - precomputation is just reasonable. Why everyone should compute the same blocks every time they start a new node?
 - if you prepare "certified" blockchain (can be GPG signed, etc.), you will show the people that you CARE about them, and about their time, and freedom of choice of downloading method. This is important for people that are hesitating about running a bitcoin daemon.

Thanks for reading.