Bitcoin Core released version 0.14 of the reference client of Bitcoin. This release contains some significant improvements in the performance, especially when building a node. Also, it changes the mempool management, enables users to retrospectively increase the fee for a transaction and many more things.
With the version number 0.14 Bitcoin Core, the reference client of Bitcoin reaches a new major release. Like the other “round” releases, it contains no changes which are in any way controversial or a soft fork but implements rather basic improvements of the software. It is a release from the machine room.
Most significant might be the performance improvements of the 0.14 release. The developers improved the script signature cache, which allows more signatures to be cached. They replaced the old Check-Points with Assume-Valid, which let the user decide by themselves up to which blocks they skips the signature verification when starting a node. Also, they enabled the process of UTXO-building to use memory formerly reserved for the mempool and refactored the P2P-networking in a way that blocks are fetched faster.
While the performance of the whole system is improved, the most notable effects might be when it comes to starting a new node. This process requires an enormous amount of bandwidth and work of CPU, memory and hard disk. According to Core, the needed time to set up a node has been reduced roughly to 50 percent. For the future of the network improvements like this are vital, as the data you need to process to start a new node will inevitably continue to grow.
Also important, but mostly for the current use of Bitcoin, is the newly introduced option to enable Replace-by-Fee (RBF) for every transaction. RBF allows users to spend an already sent, but unconfirmed output again. Miners who have activated RBF will be able to replace an old transaction with a new one with the same input if fees are higher. A newly introduced “bumpfees” command enables the user to use RBF to increase the charges for a transaction retrospectively. Which is something many users who experienced stuck transactions in the mempool might wish to do.
The same environment, Bitcoin currently faces - the beginning of a fee market - makes another new feature of Bitcoin Core interesting; instead of clearing the pool of unconfirmed transactions it has collected - the so-called mempool - on shutdown, it saves and rebuilds them when booted again. This new feature saves a lot of bandwidth consumption, which nodes needed with a full mempool to request and receive the transactions again to remember the mempool - and to get and answer the request from other rebooting nodes.
In addition to this, there are many further changes in Core 0.14, some smaller and many bigger improvements, covering every aspect of Bitcoin; the RPC API, blocks, transactions, P2P, networks, validation, building, GUI, wallet and so on.
For example, there are remarkable changes in the policy of the mempool, the management of pruning, the handling of P2P connections and much more. You can read more about Core 0.14, with the release notes available on the Bitcoin Core website.