In a Reddit post, Ethereum co-founder Vitalik Buterin published an analysis explaining “reasons why chain capacity has increased by 9% after the London upgrade”
The average gas used per day was 100 billion at the time of reporting, which was 9% more than the 92 billion consumed before the London hard fork upgrade. Buterin drafted three major reasons for the sudden rise namely the Ice age delay, blocks not employing the full 15M capacity, and the base fee adjustment.
Providing an in-depth detail, Buterin explained that the London hard fork postponed the ice age that had just begun to take effect. This allowed the average block time to reduce from 13.5 seconds to the long-term normal level of about 13.1 seconds.
Secondly, Buterin mentioned that pre-London, the largest block of gas usage was 15M. However, the maximum capacity was not employed by all the blocks because the remaining space was too small to accommodate a transaction. The London upgrade made 15M the target, rather than the maximum capacity. He wrote:
“This means that if average gas used, including the empty blocks, is below 15M, the basefee will decrease until the average is back to 15M.”
Lastly, Buterin mentioned the mathematical imperfections in basefee adjustment. He explained that there is a complex relationship between the arithmetic mean and the geometric mean that did not allow the EIP-1559 formula to achieve a 50% utilization rate perfectly. He explained:
“A 0% full block decreases the basefee by 12.5% (multiplies it by 7/8). A 100% full block increases the basefee by 12.5% (multiplies it by 9/8). So what happens if you have a 0% full block followed by a 100% full block? The basefee is multiplied by 63/64. Hence, for the basefee to remain constant, you actually need the average usage to be slightly above 50%.”
If each block is 50% full, the base fee would remain the same for each one. He explained that to fix such oddity, the basefee adjustment mechanic might need to be “explicitly exponential”.
Concluding the research, he wrote:
“But for now, Ethereum users can rejoice in the unintentionally 6% increased capacity that London brought.”