Author

Topic: Downloading the Blockchain.... (Read 1270 times)

legendary
Activity: 905
Merit: 1012
September 12, 2013, 12:31:30 PM
#13
It's not streamed reads, but random reads over a multi-gigabyte dataset. Spinning metal disks are notoriously bad at that.
legendary
Activity: 1540
Merit: 1002
September 12, 2013, 10:59:24 AM
#12
The main choke point of most long downloads is ISP's they dont like this kind of traffic as it stresses there network more than normal web browising and it makes them cry....

hell old IDE drives have higher read writes than your bandwidth RAM isnt a problem CPU isnt a problem....

my recommendation is if your struggling rent or sign up for a VPN for a day or 2
took me less than a day to download the entire blockchain on my 12mbps line Smiley (my ISP dosnt care what kind of traffic you use)
a VPN stop your ISPs from slowing down or thottleing you connection speed as easy

legendary
Activity: 905
Merit: 1012
September 10, 2013, 05:21:17 PM
#11
Guys, u r talking about USA and high-end computer users. What about the rest of the world?

The point is that the OP was not maxing out his bandwidth. It is possible to use your full bandwidth to download the blockchain, if you're selective about what peers you connect to, no matter where in the world you are connecting from. In 0.9 this manual tweaking should no longer be needed.
legendary
Activity: 2142
Merit: 1010
Newbie
September 10, 2013, 05:16:18 PM
#10
Guys, u r talking about USA and high-end computer users. What about the rest of the world?
legendary
Activity: 905
Merit: 1012
September 10, 2013, 04:19:17 PM
#9
I've had success killing and restarting bitcoind until I'm syncing from a fast peer (maxing out my bandwidth). I know others have had success using -connect using an IP in a known-to-be-fast range (e.g, if you're bootstrapping on AWS, dig the DNS seed until you find a peer with an AWS IP). Sync time goes down to less than a day even with a spinning metal disk.
staff
Activity: 4284
Merit: 8808
September 10, 2013, 02:59:31 PM
#8
Strange I bootstrapped a node from genesis block to current in less than 18 hours.
Slowness these days is mostly due to cruddy peers combined with bitcoin's poor handling of cruddy peers. The work in progress for 0.9 (headers first) improves this enormously. (e.g. down to a couple of hours on my DSL test)
donator
Activity: 1218
Merit: 1079
Gerald Davis
September 10, 2013, 10:17:19 AM
#7
Strange I bootstrapped a node from genesis block to current in less than 18 hours.  Smiley  As others have pointed out sufficient memory (bitcoind doesn't seem to use >2GB regardless of available resources) and fast disks are far more important than bandwidth speed.   I think you will find if you monitor your network connectivity your average download speed is nowhere near the linespeed of your ASDL connection (20Mbps = 9GB per hour).

kjj
legendary
Activity: 1302
Merit: 1026
September 10, 2013, 10:11:48 AM
#6
The main choke point of blockchain sync speed is your hdd not your internet speed.  If you have a solid state drive and/or a RAID array it will dramatically decrease your blockchain sync time.  You can also add dbcache="number_of_mb_of_RAM_to_use" to bitcoin.conf to decrease the strain on your hdd while syncing.

P.S. Default value for dbcache is 25 and a good value for a computer with 4gb ram is 3000, assuming you aren't doing anything RAM intensive.


The box I am using has 512MB of ram, :-) I found it on the street and was curious to see how bare-bones a node could run. Pentium duel core. I'll get more stats when it's finished and I check out the bios. I didn't know however that RAM influenced the download, but now I see.

After the initial verification, it should be fine.  Well, fine-ish.

I have two nodes running on an old Athlon XP 1800+ with 883 MB reported memory.  It runs fine most of the time, but bogs down a bit when the network is growing quickly and blocks come too fast, or when feeding a newly started node.  A single node, or even a dual that disallows incoming connections, would probably be fine.

While the bottleneck is certainly in your machine, the speed of your first peer can also be a factor for faster machines.  I also run some diskless nodes that maintain the entire datadir in a RAM drive.  While I haven't done any scientific measurements, just by watching the logs it is obvious how much faster the RAMdisk node is when feeding a new node's initial block download.
legendary
Activity: 1204
Merit: 1002
RUM AND CARROTS: A PIRATE LIFE FOR ME
September 10, 2013, 06:36:26 AM
#5
The main choke point of blockchain sync speed is your hdd not your internet speed.  If you have a solid state drive and/or a RAID array it will dramatically decrease your blockchain sync time.  You can also add dbcache="number_of_mb_of_RAM_to_use" to bitcoin.conf to decrease the strain on your hdd while syncing.

P.S. Default value for dbcache is 25 and a good value for a computer with 4gb ram is 3000, assuming you aren't doing anything RAM intensive.


The box I am using has 512MB of ram, :-) I found it on the street and was curious to see how bare-bones a node could run. Pentium duel core. I'll get more stats when it's finished and I check out the bios. I didn't know however that RAM influenced the download, but now I see.
sr. member
Activity: 336
Merit: 250
Cuddling, censored, unicorn-shaped troll.
September 09, 2013, 06:18:19 PM
#4
So I decided to try downloading the blockchain on a normal ADSL connection (20mb line, supposedly). I'm nearing the end of my first week of downloading 24/7 and I still don't have the whole thing yet. I've even added some of the most well connected nodes.

It's an academic exercise of course, I know I could torrent the thing first, but wow- that blockchain.

You might wanna try this one : https://bitcointalksearch.org/topic/ann-bitcoin-blockchain-data-torrent-145386
Or maybe wait for the next update, august 30 is pretty old, already.

EDIT : Ok, read too fast. You knew... Then you're not asking for help, just switch to fiber. Grin
legendary
Activity: 2058
Merit: 1452
September 09, 2013, 08:45:00 AM
#3
It's an academic exercise of course, I know I could torrent the thing first, but wow- that blockchain.
So why are you posting this in technical support? You don't need support so stop crying wolf. Hell, why are you posting this at all? Anyone moderately interested in bitcoin should know the blockchain is 10gb.
hero member
Activity: 533
Merit: 500
^Bitcoin Library of Congress.
September 09, 2013, 08:00:21 AM
#2
The main choke point of blockchain sync speed is your hdd not your internet speed.  If you have a solid state drive and/or a RAID array it will dramatically decrease your blockchain sync time.  You can also add dbcache="number_of_mb_of_RAM_to_use" to bitcoin.conf to decrease the strain on your hdd while syncing.

P.S. Default value for dbcache is 25 and a good value for a computer with 4gb ram is 3000, assuming you aren't doing anything RAM intensive.
legendary
Activity: 1204
Merit: 1002
RUM AND CARROTS: A PIRATE LIFE FOR ME
September 09, 2013, 03:19:25 AM
#1
So I decided to try downloading the blockchain on a normal ADSL connection (20mb line, supposedly). I'm nearing the end of my first week of downloading 24/7 and I still don't have the whole thing yet. I've even added some of the most well connected nodes.

It's an academic exercise of course, I know I could torrent the thing first, but wow- that blockchain.
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