Quote from: ATguy on March 09, 2016, 09:07:22 PM

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The worst case block validation costs that I know of for a 2.2 GHz CPU for the status quo, SegWit SF, and the Classic 2 MB HF (BIP109) are as follows (estimated):

1 MB (status quo): 2 minutes 30 seconds (19.1 GB hashed)
1 MB + SegWit: 2 minutes 30 seconds (19.1 GB hashed)
2 MB Classic HF: 10 seconds (1.3 GB hashed)

Two things:
1) These are apparently estimations; so this is inadequate data. Blocks differ in size, and types of transactions in them.
2) The comparison makes little sense as they've added a hard limit in Classic.

Quote from: David Rabahy on March 09, 2016, 10:11:55 PM

When I play this out in my mind I see this;

1) eventually SegWit gets out the door and is adopted but if it doesn't reduce verification times then what was the point?

Segwit:
1) More transaction capacity
2) Fixes TX mallaeability
3) New mechanism for adding OPcodes
4) More flexible security model (fraud proofs)
5) Potential bandwidth decrease for SPV nodes.

Linear scaling of sighash operations
A major problem with simple approaches to increasing the Bitcoin blocksize is that for certain transactions, signature-hashing scales quadratically rather than linearly.

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Segwit resolves this by changing the calculation of the transaction hash for signatures so that each byte of a transaction only needs to be hashed at most twice. This provides the same functionality more efficiently, so that large transactions can still be generated without running into problems due to signature hashing, even if they are generated maliciously or much larger blocks (and therefore larger transactions) are supported.

Who benefits?

Removing the quadratic scaling of hashed data for verifying signatures makes increasing the block size safer. Doing that without also limiting transaction sizes allows Bitcoin to continue to support payments that go to or come from large groups, such as payments of mining rewards or crowdfunding services.

The modified hash only applies to signature operations initiated from witness data, so signature operations from the base block will continue to require lower limits.

Quote from: David Rabahy on March 09, 2016, 10:34:16 PM

Whatever; I've removed Core 0.12 and am now running Classic 0.12. I am unsettled.

I thought better of you at times. I guess I was wrong.