Initial sync of the Bitcoin QT client

[SilverandBitcoins]

I've installed the Bitcoin QT client on my MacBook.  I'm still trying to sync it - it has been taking a long time.  When I installed the wallet for LTC and PPC on a windows desktop it didn't take nearly as long.  Last night when I went to bed it was at 82% and this morning it's over 88%.  Is that unusual?

[J.Jade]

It's not unusual - I've experienced the same.

The other crypto currencies are younger and have less transactions -> less data to download.

[Gabi]

Syncing=downloading the whole blockchain, wich contains all the transactions ever happened.

Right now the bitcoin chain is like 8GB big and the client also verify it while it download it. No wonder syncing LTC or PPC is much faster, almost no one use them 

[szym00]

Did you think about that what will happen in e.g. 2050 with this 'bitcoin chain'? Will it increase from 8GB to e.g. 8TB?

[J.Jade]

Did you think about that what will happen in e.g. 2050 with this 'bitcoin chain'? Will it increase from 8GB to e.g. 8TB?

If bitcoin ever goes mainstream I think 8 TB is too low to be considered a reasonable estimate for the year 2050...

[caveden]

Yes, people have thought about it. There's plenty of material on this forum, on the wiki, the Bitcoin Magazine print version ran an article on it etc.

OP: you don't need to use bitcoin-qt if you want it to be ready fast. You can use something like Multibit for example, it uses SPV.

[DannyHamilton]

Did you think about that what will happen in e.g. 2050 with this 'bitcoin chain'? Will it increase from 8GB to e.g. 8TB?

If bitcoin ever goes mainstream I think 8 TB is too low to be considered a reasonable estimate for the year 2050...

Actually I think it's too high given the current protocol.

Assuming the protocol doesn't change, there is currently a 1 megabyte maximum size for a block.  A block is added to the blockchain approximately every 10 minutes.

So, there is a maximum (on average) of:

6 megabytes added to the blockchain every hour.

6 MB * 24 hr = 144 megabytes added to the blockchain every day.

144 MB * 365 days = 52,560 MB / 1024 MB per GB = 51.33 gigabytes added to the blockchain every year.

51.33 GB * 37 years = 1900 GB / 1024 GB per TB = 1.85 terabytes added to the blockchain by 2050.

51.33 GB is approximately 0.05013 TB, so to reach 8 terabytes in size, it would take:

8 TB / 0.05013 TB per year = 159.6 years (which is more like 2172 than 2050).

[J.Jade]

Did you think about that what will happen in e.g. 2050 with this 'bitcoin chain'? Will it increase from 8GB to e.g. 8TB?

If bitcoin ever goes mainstream I think 8 TB is too low to be considered a reasonable estimate for the year 2050...

Actually I think it's too high given the current protocol.

Assuming the protocol doesn't change, there is currently a 1 megabyte maximum size for a block.  A block is added to the blockchain approximately every 10 minutes.

...

Will it always be 1 MB / block - can this be changed? Will this suffice to process all transactions in future?

[caveden]

Assuming the protocol doesn't change, there is currently a 1 megabyte maximum size for a block. 

Such assumption is not reasonable.

Will it always be 1 MB / block - can this be changed? Will this suffice to process all transactions in future?

Surely it can change, and likely will.
It's also likely that there will be people that will insist in remain in the "old version" where no more than 1Mb blocks can exist. That will provoke a fork. This will provoke lots of turbulence in the short run. In the long run, the scalable Bitcoin will "win".

[DannyHamilton]

In the long run, the scalable Bitcoin will "win".

This is an opinion and an assumption.  It is not known which will "win" or even that the a fork to increase blocksize would get enough traction to be noticed.

Will it always be 1 MB / block - can this be changed? Will this suffice to process all transactions in future?

There has been significant debate about this between many of the developers as well as many of the members of the bitcoin community.

There are significant issues on both sides of the debate.  Increasing the blocksize too much can result in driving small mining operations out and can result in significantly less people running full peers.  This could result in a substantial reduction in the security of bitcoin.

Additionally, if a consensus can't be reached among all users the blockchain would split.  Coins received prior to the split could be spent on both blockchains.  Coins received after the split could only be spent on the blockchain where they were received.  In some circumstances, if someone receives "split" coins on one blockchain, they could potentially steal the same coins on the other blockchain without knowing the private key since the required signature would be the same.

As caveden stated, there would be lots of "turbulence".  You might even call it chaos. It is difficult to predict what would result from the chaos.  Perhaps there would end up being two stable coin systems that both have substantial support and coexist.  Perhaps one blockchain would eventually die off as people chose more and more to use the other.  Perhaps the chaos would damage the faith people have in bitcoin enough for both blockchains to die as people migrate to some other currency entirely.

[szym00]

8 TB / 0.05013 TB per year = 159.6 years (which is more like 2172 than 2050).

uhh... but I think that in this year that will not be my problem

[J.Jade]

@ DannyHamilton

Thank you for shedding some light on this.

[SilverandBitcoins]

How much free space should someone have - like on my Macbook - to install Bitcoin QT?

[TaxReturn]

around 7GB + headroom ~ 10 GB if you still want to save some cat pics

[DannyHamilton]

How much free space should someone have - like on my Macbook - to install Bitcoin QT?

It depends on how long you intend to run the client.

At the moment, if you only want to run it for a few weeks, you can probably get by with 8 or 9 GB.

However, the blockchain grows with every new block solved, and blocks are solved approximately every 10 minutes.

There is potential for the blocksize to increase to 1 megabyte very soon.  As such, if you want to run Bitcoin-Qt on that computer for more than a year, you'll want to have at least 60 gigabytes free.