F2Pool, the world's largest Bitcoin mining pool, maintains that changing its code to allow bigger blocks through BIP 101 or Bitcoin XT is not an option.
Wang Chun, the operator of the China-based pool controlling some 20 percent of hashing power, dismissed the idea of an exponential growth rate of the maximum block size for 20 years leading to 8-gigabyte blocks.
Asked by Bitcoin Magazine, Chun said: “We cannot predict what will happen years into the future, and we think a first step to 2 megabytes should be enough for now.”
The block-size dispute – which represents a tradeoff between the number of transactions the Bitcoin network can handle and its decentralization – might reach a critical juncture over the next weeks. A large segment of Bitcoin's development community will discuss the issue at the upcoming Scaling Bitcoin workshop in Hong Kong in the first week of December, while several prominent Bitcoin companies have stated they intend to change their code to allow for bigger blocks that same month.
Chun, too, believes that raising the block-size limit is an urgent matter, explaining:
“I think it is urgent, because the transaction volume is increasing on the blockchain, and if the price rises in near future, it will push the transaction volume to be even higher. I think the max block size should be raised as soon as possible, but it should not be raised too much. Two megabytes is preferred as the first step.”
One possible solution, BIP 101, is programmed to increase the maximum block size to 8 megabytes if a threshold of 75 percent of mining power accepts the change. Once activated, this limit is set to double every two years for 20 years, ultimately leading to an 8-gigabyte block-size limit.
This patch, which is designed by former Bitcoin Core lead developer Gavin Andresen, was implemented in Bitcoin XT, the alternative Bitcoin implementation run by Google veteran Mike Hearn. BIP 101 is also favored by severalprominent Bitcoin companies, as well as Slush Pool.
Switching to BIP 101 or Bitcoin XT is a bad idea; we will never do that,” Chun reiterated his earlier position. “After a meeting with some other Chinese pools earlier this year, we proposed an 8-megabyte limit, because we thought Gavin's initial 20 megabyte proposal was too big for us. I always thought 2 megabytes would be better as a first step, but I did not want to offend Gavin with a 10 times smaller proposal. Gavin then answered us with BIP 101, which due to its steep growth curve is essentially 8 gigabytes, so it’s done. I don’t trust Gavin anymore – nor Hearn for that matter.”
On the Bitcoin development mailing list, Chun recently suggested raising the maximum block size in accordance with the block halving. As such, the block-size limit would be raised to 2 megabytes as soon as possible, followed by an increase to 4 megabytes halfway through 2016, up to 32 megabytes by 2028.
Alternatively, Chun said he would be willing to implement an incremental increase to 8 megabytes over four years, as proposed by Blockstream CEO and hashcash inventor Dr. Adam Back. This “2-4-8” option seems acceptable to a significant segment of the Bitcoin Core development team, as well as some prominent industrymembers.
And even though Back proposed 2-4-8 as a temporary solution, Chun suggested that it could even be more than that.
We do not necessarily consider an 8 megabyte block-size limit a temporary solution. We don’t know what will happen moving forward. But we definitely think 8 megabytes is enough for the foreseeable future. Presumably, at least for the next three to four years.”