For the first time ever, a 1.6MB bitcoin block was mined yesterday by a small pool called Bitcoin India which currently handles just 0.2% of network hashrate.

Block 493,182 contained 833 transactions with 11,073 inputs and outputs, transfering nearly $50 million worth of bitcoins for a considerable fee of $5,600.

The average bitcoin blocksize has gone slightly down yesterday to 1.03MB from 1.04MB. The above block, therefore, might be an exception with Jonathan Toomim stating:

“As with previous instances of large blocks, almost all of this block’s space was taken up by one entity. This entity sent 36 large (33.7 kB) multisig transactions, each of which had 201 inputs and one output.

The following block had 14 of these 33.7 kB multisig transactions. All told, that’s 1685 kB in 50 transactions from a single entity. This is likely the same entity that caused the previous bursts of large blocks.”

In effect it appears there is an entity that is heavily using segwit. Thus making the above transactions to presumably save on fees.

But now that we are seeing these slightly bigger blocks, claims are being made that segwit’s method of increasing capacity is actually very inefficient.

In comparing some numbers the 1.6MB block had:

Block size: 1602023

Number of transactions: 833

Input count + Output count: 11073

Bytes per IO address: 144

While a random non-segwit block (483,182) had:

Block size: 999931

Number of transactions: 2110

Input count + Output count: 10574

Bytes per IO address: 95

The segwit block, therefore, which is near the practical limit of bitcoin’s current blocksize rules, was able to handle only 500 more inputs and outputs out of some 11,000. Making it an increase of just 5%, instead of 50% as would be the case for a non-segwit 1.6MB block.

That may be because segwit blocks require more complex transactions that need far more space than non-segwit blocks. Which might translate to bitcoin gaining no, or very minimal, on-chain capacity through segwit.

Which may be shown by the fact fees have reached $5 per transaction recently while the network remains congested as its capacity continues to be very limited with it all operating at a dial-up, or worse, level.