Nostr Web Client

Indeed. 4MB/block max, and usually much less. Mempool size is already growing much more slowly than the capacity of storage devices. Not to mention, you can do just about everything you could possibly need to with a pruned node running on a 20GB drive.

crany 👽🧡🗿 4mo ago 💬 2

Chat GPT-4:

## Bitcoin Core Mempool Maximum Limit

Bitcoin Core does not have a fixed upper limit for the mempool size in the traditional sense. However, significant changes are coming with the release of **Bitcoin Core v30**, scheduled for **October 2025**. This version will alter how the mempool handles data, particularly regarding the **OP_RETURN** outputs.

### Key Changes in Bitcoin Core v30

1. **Removal of the 80-byte Limit**: The previous default limit of **80 bytes** for OP_RETURN data will be eliminated. Instead, nodes will be able to accept up to **4MB** of arbitrary data per output. This change is expected to significantly increase the amount of data that can be included in transactions.

2. **New Configurability Settings**: The setting known as **datacarriersize** will be redefined. Previously, this setting controlled the amount of data allowed in a single OP_RETURN output. In v30, the same numerical value will now permit **nine times more data** than before, effectively allowing for **830 bytes** of arbitrary data if the user specifies **83**.

3. **Default Behavior Change**: The default mempool policy will no longer filter out large OP_RETURN transactions, which means that the network will be more permissive regarding the types of data included in transactions.

### Implications of These Changes

- **Increased Mempool Size**: While there isn't a strict upper limit on the mempool itself, the changes will allow for a much larger volume of data to be processed and stored temporarily. This could lead to increased congestion if many large transactions are submitted simultaneously.

- **Community Reactions**: The changes have sparked debate within the Bitcoin community. Supporters argue that this modernization is necessary for Bitcoin's evolution, while critics warn that it could lead to network bloat and detract from Bitcoin's primary function as a currency.

In summary, while Bitcoin Core does not impose a strict upper limit on the mempool, the upcoming changes in version 30 will significantly alter how data is handled, potentially leading to a much larger effective mempool size.

Reply to this note

Please Login to reply.

Discussion

m00ninite 4mo ago

Not sure what you're trying to tell me with a page AI slop paste. Care to tell me in your own words what I should be focusing on?

crany 👽🧡🗿 4mo ago 💬 2

a node's mempool is configurable as a portion of the machines RAM. there's no hard limit except infrastructure a node is running on

m00ninite 4mo ago 💬 1

Indeed. I recall mempool.space had to increase their official node's mempool limit since transactions weren't showing up with the default limit.

crany 👽🧡🗿 4mo ago

so which "indeed" is it? your two seem mutually exclusive to me. is there a hard limit or is it configurable?

https://bitcoincore.org/en/doc/29.0.0/rpc/blockchain/getmempoolinfo/

m00ninite 4mo ago

I think our wires are getting crossed. When Bill said "mempool already has a hard cap", he meant the size of blocks is limited, by consensus. The size of the mempool (the *entire* mempool, including the backlog) is configurable per-node.