2MB Block Limit Increase Pros and Cons


Well-Known Member
Mar 13, 2016
2MB Block Limit Increase
Double transaction capacity

Improved user experience, ( no more threads about a TX taking a long time to get confirmations )
temporary effect

Makes sustained spam attacks much more costly to accomplish. (Basically, doubles the cost of an attack, or limits its duration to 1/2 as long)
temporary effect
minimal effect, at 1-5cent fee / TX, It still is cheap to spam the free space the 1MB of extra space provides.
spam is OK, it simply increases total fees collected by miners

More fees potentially collected by miners on each block

Business can operate with less fear of being outed from the network because high fees

Renewed trust in the development process and in the network scalability capacity
Bitcoin users will stop dumping their coins in favor of alternative coin like ETH.

Less reliance on side chains, LN, and centralized payment processors to handle TX.
It's likely that most users will end up using centralized payment processors to process their smaller value TX, centralized payment processors could employ fractional reserves, and all kinds of other nasty things bitcoin was meant to solve.

More adoption
BTC value will rise as a result

We maintain the positive correlation between price and volume
TX volume was never meant to be capped, not allowing the block limit to rise is a change in and of itself

Not bumping limit to 2MB could cause a fork.
It's no secret poeple want 2MB, we've seen open letters signed by many many top bitcoin businesses stating they want bigger blocks, we've also see the same thing coming from the a huge % of hashrate, it's not unreasonable to assume, inaction on this issue will cause a fork.

Requires hard fork
There is a risk of splitting into 2 chains, but properly implementing the hardfork with a 75% threshold and lengthy grace period, makes the risk of a "war" breaking out filled with pain & confusion for users and merchant, unlikely

Increased resource usage (capacity, bandwidth, processing power)

If the user base shrinks it will put an unnecessary burden on a smaller user base.
They can always change it back, But also it is just limit, not actual block size, miners can use any soft limit they want, like they did when we had a 1MB limit but the miners had a soft limit of 256KB

The possibility exists to construct a TX that takes too long to validate
easily mitigated through the use of soft limits imposed by miners limiting the number of inputs a TX can have.

Increased chance for orphan blocks.
more data required, it is believed the effect will be minimal but we have no hard data either way

Sets a bad precedent for changing consensus rules, and can lead down a slippery slope.
The change wasn't done lightly it tooks years of debate.

2MB wouldn't be a final solution, this makes a lot of Pros a temporary effect, and we won't achieve similar scalability to other payment methods like VISA
bitcoin doesn't have 800 million users. bitcoin has ~2 million users 2MB will satisfy the current number of users and allow for some growth
2MB might not be the ultimate scaling solution, but alongside segwit and Lighting Network we can scale bitcoin beyond VISA like capacity.

Less adoption, network latency will increase, potentially forcing some full node clients with high latency or low bandwidth connections from participating. (think small African village in bum fuck nowhere for instance)
SPV clients mitigate this issue.

Black Text Is a Pro or Con related to a 2MB block limit.
Green Text Is used to highlight key points which give the Pro or Con more validity
Red Text Is used to highlight key points which debunk or lessen the validity of the Pro or Con

We are compiling a list of some basic pros and cons for a 2MB HF. please post below some Pros or Cons to a 2MB block limit, and discuss them. Feel free to try and debunk the pros / cons i will try and follow the discussion and summarize / post links to these posts with more information. Free feel to ask me to reword a Pro or Con listed in OP for added clarity, please provide full text as you believe it should appear.

OP will not include any reference to Core or Classic, only the pros and cons of a 2MB block limit increase, pure and simple.

This time next year Core will be looking for wide spread consensus before raising block limit to 2MB, Its is my hope that this Pro & Con List will help users and miners understand all the specific issues related to block size limit. so they can be confident about their decision to vote for a limit increase or not.

Thank you for your input!


Active Member
Mar 14, 2016
^^ There it is. This post will write Bitcoin history just like the WO did.