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Other => Beginners & Help => Topic started by: realme on June 18, 2012, 12:01:52 PM



Title: Bitcoin slow to download the block chain?
Post by: realme on June 18, 2012, 12:01:52 PM
Hello,
 yet I am only allowed to ask in Newbies Forum. So I repost the question here.
Quote from: bionicghost
the block chain has been downloading at an excrucuatingly slow pace [about 1 block per 5 seconds].
https://bitcointalk.org/index.php?topic=67231.msg782085#msg782085
I have same problem as this user, but I get only [1 block per 18 seconds]!

Yes I have bitcoin-qt 0.6.2
Yes, I do prtforwarding 8333

1. Solve "You can download a premade blockchain + index, but that implies a certain amount of trust in the supplier of the files, as they are not verified as thoroughly that way."

But what is the cause of slowness?
What does it mean in the quoted thread above? "The slow part is not downloading the blockchain, it's verifying it and building a transaction index for it (the blkindex.dat file)."?

I have an Intel Core " Duo @2.40Ghz, 2 GB Ram". But I dont see any strange behaviour of  bitcoin-qt in Taskmanager CPU column!


Title: Re: Bitcoin slow to download the block chain?
Post by: Newar on June 18, 2012, 12:04:12 PM
You get it here: http://sourceforge.net/projects/bitcoin/files/Bitcoin/blockchain/


Title: Re: Bitcoin slow to download the block chain?
Post by: realme on June 18, 2012, 12:10:30 PM
You get it here: http://sourceforge.net/projects/bitcoin/files/Bitcoin/blockchain/
Thanks!
But that seems not what I need. It says "Who needs this? - Any first-time user of bitcoin, who wishes to avoid the lengthy block chain download through the p2p network."

I need a solution for daily use. I cant download the daily blockchains of a few hundred and spend hours of downloading while my computer is freezing.  ???

Who knows: what is the cause of slowness?


Title: Re: Bitcoin slow to download the block chain?
Post by: Newar on June 18, 2012, 12:32:55 PM
So did you download the whole block chain once already? You will not have to download it every day over and over again. It will just go and get the missing pieces since last program start.

And yes, it is a slow process, hence the file at soureforge.


Title: Re: Bitcoin slow to download the block chain?
Post by: skrubis on June 18, 2012, 12:58:28 PM
Mine took more than 4 days to sync with the network. It was mainly because I was unable to enable upnp or open the bitcoin port, so I was unable to connect to more that 8 nodes at a time.

You should:

1) open port 8333 on your router/firewall for TCP (or was it UDP)
2) if you are unable to do ^this, try connecting to any open wireless hotspot, I noticed that I was able to connect to much more nodes that way with a slow open wifi port and sync faster than using my own 200mbit optic cable that is crazy fast.


Title: Re: Bitcoin slow to download the block chain?
Post by: StewieMcFluffy on June 18, 2012, 01:00:54 PM
You get it here: http://sourceforge.net/projects/bitcoin/files/Bitcoin/blockchain/
Thanks!
But that seems not what I need. It says "Who needs this? - Any first-time user of bitcoin, who wishes to avoid the lengthy block chain download through the p2p network."

I need a solution for daily use. I cant download the daily blockchains of a few hundred and spend hours of downloading while my computer is freezing.  ???

Who knows: what is the cause of slowness?
It will most likely take you a day or so to download most of the blockchain, if you decide not to use the sourceforge link or any pre-downloaded blockchain to get a head start.
How many blocks have you downloaded so far? Were currently on block 185132 at the moment


Title: Re: Bitcoin slow to download the block chain?
Post by: mollison on June 18, 2012, 01:48:24 PM
Are you using disk encryption? I've been told that can massively slow things down. Seems to be true from firsthand experience.


Title: Re: Bitcoin slow to download the block chain?
Post by: keverw on June 21, 2012, 07:20:11 PM
Mine took like 20 hours. Didn't know they had pre downloaded block downloads. Will be helpful for next time I install Bitcoin, Like on my server!


Title: Re: Bitcoin slow to download the block chain?
Post by: Gabi on June 21, 2012, 07:42:01 PM
Quote
But what is the cause of slowness?
The epic usage of the hard disk by the client. It keep reading and verifying  each block wich cause epic hard disk usage wich is then the bottleneck


Title: Re: Bitcoin slow to download the block chain?
Post by: realme on July 01, 2012, 09:08:48 PM
Hello,

thanks for all your reply's.
But many of you didnt understand, what I was meaning (Maybe because my not native English?).
Its not about "using disk encryption", or "portforwarding 8333 on router/firewall"... I was connected > 20 nodes.

The problem is, if I have all actual blocks of e.g 187,086 today. In a few days I have do update the new blocks!
And e.g today (with bitcoin-0.6.3-win32) it tooks five hours to load/verifying  ca. 1200 blocks. In this time its not possible to use my Laptop for other work!

Quote
But what is the cause of slowness?
The epic usage of the hard disk by the client. It keep reading and verifying  each block wich cause epic hard disk usage wich is then the bottleneck
Ok, understand. Its really mainly the HDD?
But how do other people?  ??? BTC is not usable like it behaves on my laptop.
Its necessary to buy a very fast hard disk (SSD)? What HDD parameters do I need to load/verifying blocks faster?

Thank you.


Title: Re: Bitcoin slow to download the block chain?
Post by: Bitsky on July 01, 2012, 09:52:01 PM
There have been numerous reports about this problem lately, mainly since Satoshidice caused a spike in transactions. In my opinion, this is a real roadblock for new users, who usually don't want to invest the time it takes for the initial download. Defenders of the status quo will mention web-based wallets (which I don't trust), or other clients (where only Electrum seems to be the only choice (if you don't want Java)).

The main client needs to be optimized in that area (I/O and pruning). Currently, it's faster (for me) to download a snapshot and only verify the last missing blocks than letting the client take care of updating 3+ days; and I'm on a slow connection.


Title: Re: Bitcoin slow to download the block chain?
Post by: zhitgeist on July 01, 2012, 10:01:57 PM
Yeah, it was very slow for me too. 15-20 hours or so.


Title: Re: Bitcoin slow to download the block chain?
Post by: zvs on July 01, 2012, 10:22:19 PM
it took less than 5hrs on my home computer, about 2 days on some crappy kimsufi, and about 15 hours on the hetzner ex 4

the entire block chain is like 2 gigs?

link speed was never an issue for me, just processing, near the end it slows to a crawl

oh, being able to use -connect to my home computer on the hetzner sped it up a lot, instead of getting all those 'such and such must have been sent to the wrong person' errors

you could try using bitcoind -connect=91.121.152.57

that's my kimsufi on celeron 1.2ghz, i think it can upload just fine though


Title: Re: Bitcoin slow to download the block chain?
Post by: casascius on July 01, 2012, 10:53:40 PM
This is a problem that will plague the main client for quite a while.  Its developers don't consider it a top issue that people have to wait forever to start using it - they presently have this idea that unless all of the calculations network-wide are repeated, anything less than that is trusting somebody and that trust could be exploited and so is unacceptable, so unacceptable that having new users wait hours is more acceptable.

Other clients start up with much less time, as they are "lite nodes".  But to the developers' credit (of the main client I mentioned first, not of the lite nodes), lite nodes are able to do this because of the environment provided by the nodes that took the time to at least acquire the whole block chain.  The network would not function if it consisted solely of lite nodes.

Meanwhile there are discussions on the forums going on right now, contemplating real good solutions to bridge the gap - how to engineer a client to not need to exhaustively verify the unabridged history of Bitcoin, but still to have it as a "full citizen" node that can sustain the network.  Those discussions look promising and may result in the emergence of a client with such capabilities, but the capabilities will really only mature when the community as a whole (users and developers) buy into the new ideas and either decide they are an acceptable tradeoff for security versus performance, or tweak the capabilities until they are.

tl;dr: The main client is going to continue to get slower and slower and slower for first startup - and downloading the pre-generated blockchain images is practically a must.  But there are real enough solutions to the problem that it will almost certainly be fixed long before the block chain file gets bigger than your hard drive!  The ultimate solution - new user running a client for the first time and needing no more than minutes to get a good sync on the Bitcoin network that is reliable enough to accurately accept all good payments and reject bogus ones - is well on the radar.  This is part of why Bitcoin is still experimental and the units of account (BTC) are still under $10 - a bargain for where I see the future of this going!


Title: Re: Bitcoin slow to download the block chain?
Post by: Tony on July 03, 2012, 04:56:46 AM
It took me about 5 second to download 1 block too even though i've already predownloaded the block chain ( about 2.5GB ) i still need to synchronize my blockchain with the 5second perblock speed :(


Title: Re: Bitcoin slow to download the block chain?
Post by: digimag on January 17, 2013, 05:41:18 PM
Hello,

I am upset by how long it takes to start using Bitcoin from scratch. It is taking more than 30 hours now, and the last 7 days are especially long to download.

I have a Macbook Air with SSD and a 10 Mbps up / 100 Mbps down of network bandwidth on optical fiber! And UPnP is working.

I don't see how waiting more than 24 hours to start can be considered as "normal" for any software. ???

And this is almost unusable for anyone who doesn't run his computer 24H/24!

I understand the importance of having the entire blockchain, but can't we just start by downloading the most recent blocks, so we can start to use the software right away, and right after that download and process the rest in the background?

What happened to developers? Isn't this obvious?


Title: Re: Bitcoin slow to download the block chain?
Post by: DannyHamilton on January 17, 2013, 07:12:27 PM
I am upset by how long it takes to start using Bitcoin . . .

If all of this is an issue for you, why did you choose to use the Bitcoin-Qt client instead of one of the "light" clients such as Electrum, Multibit, or even a web wallet like blockchain.info?

. . . I understand the importance of having the entire blockchain, but can't we just start by downloading the most recent blocks, so we can start to use the software right away, and right after that download and process the rest in the background? . . .
Based on your question, I'd say that you don't understand the importance of having the entire blockchain.  The most recent blocks are useless unless you have the older blocks.  Everything in the bitcoin blockchain simply refers back to something previous until you get back to the coinbase transaction.  A recent block will have a bunch of transactions that claim to get their value from older transactions.  Without those older transactions, there is no way to determine if the transactions you are looking at in the current block are valid.

The "balance" in your wallet is simply the total of all the valid previous transactions from all the old blocks that have ever used your addresses in their output.  Without the old blocks, how will the client add up those transactions?


Welcome back to bitcointalk.org.  I see you haven't actively posted in 15 months.  A lot has happened since then. In particular the new 0.8.0 release of Bitcoin-Qt which is not quite yet ready will reduce some of the issues people have with the blockchain.


Title: Re: Bitcoin slow to download the block chain?
Post by: Schabooza on January 17, 2013, 07:40:38 PM
I am upset by how long it takes to start using Bitcoin . . .

If all of this is an issue for you, why did you choose to use the Bitcoin-Qt client instead of one of the "light" clients such as Electrum, Multibit, or even a web wallet like blockchain.info?
Maybe the reason is the following sentences on Bitcoin.org
Quote
The original software written by Satoshi Nakamoto, the project's founder. If you aren't sure which program to pick, this is a good bet.
I think Newbies getting often trapped by that (like me too^^)


Title: Re: Bitcoin slow to download the block chain?
Post by: DannyHamilton on January 17, 2013, 07:45:59 PM
I am upset by how long it takes to start using Bitcoin . . .

If all of this is an issue for you, why did you choose to use the Bitcoin-Qt client instead of one of the "light" clients such as Electrum, Multibit, or even a web wallet like blockchain.info?
Maybe the reason is the following sentences on Bitcoin.org
Quote
The original software written by Satoshi Nakamoto, the project's founder. If you aren't sure which program to pick, this is a good bet.
I think Newbies getting often trapped by that (like me too^^)
Yeah, I figure that is probably the reason.  My question was more of a rhetorical way of suggestion to try one of the other clients than a serious question as to why the Bitcoin-Qt client was chosen.


Title: Re: Bitcoin slow to download the block chain?
Post by: Gabi on January 17, 2013, 10:18:16 PM
Use a lightweight client like multibit

Yes it is very slow and yes it is a problem and that's why they are working on a new database system wich will make downloading the blocks much much faster.  This said, use lightweight clients


Title: Re: Bitcoin slow to download the block chain?
Post by: b!z on January 18, 2013, 07:25:01 AM
If you use an online wallet, like blockchain.info/wallet, or a client like Electrum, you won't have to worry about this.