Quote from: jl777 on March 17, 2016, 01:24:14 AM

I was told the extra space needed was 2 bytes per segwit tx plus 1 byte per vin, though maybe the 1 byte per vin can be reduced to 1 bit. Not sure how that is possible without new script opcodes, so maybe that is a possibility in the fullness of time sort of thing.

I think it might actually be 33 bytes per vin because of the implementation being used which does not introduce the new address type. This is so that the p2sh script will still verify true to old nodes. It is a 0 byte followed by 32 byte hash of the witness.

Quote from: jl777 on March 17, 2016, 01:24:14 AM

Regardless, the total space needed is more for segwit tx than normal tx, this is confirmed by wuille, lukejr and gmaxwell.

now I never said segwit wasnt impressive tech as that is quite a small overhead. my point is that segwit does not reduce the permanent space needed and if you feel that the HDD space needed to store the blockchain (or the data need to be shared between full nodes) is a factor that is important to scalability, then segwit does not help scalability regarding those two factors.

And I don't think that anybody has ever said that it would reduce the space needed to store it. If you are believing everything you read on the internet, you need a reality check. When you read these things, make sure that they are actually backed up by reputable sources e.g. the technical papers.

Quote from: jl777 on March 17, 2016, 01:24:14 AM

I do not speak about any other factors, only the permanent space used. Originally I was told that segwit did everything, including allow improved scalability and what confused me was that it was presented in a way that led me (and many others) to believe that segwit reduced the permanent storage needed.

Could you cite the article(s) which did that? If it was something on bitcoin.org or bitcoincore.org then that could be fixed.

Quote from: jl777 on March 17, 2016, 01:24:14 AM

now this is clarified that segwit does not reduce the space needed and that segwit softfork will force any node that wants to be able to validate setwit tx to also upgrade to segwit, then I think the rest is about implementation details.

Sure. Any other questions about implementation?

Quote from: jl777 on March 17, 2016, 01:24:14 AM

And maybe someone can clarify the text on the bitcoincore.org site that presents segwit as curing cancer and world hunger?

Does it portray segwit that extremely positive? I read it and it didn't seem that way to me.