Bandwidth and Memory Tweaks in v0.12

[ghost]

There are new settings in version 0.12 that allow you to change the way your node behaves and can be used to tweak bandwidth and memory consumption.

The new options for bitcoin.conf are

blocksonly=0
mempoolexpiry=72
maxmempool=300
maxorphantx=100
maxuploadtarget=0

blocksonly is an option that configures your node to only relay blocks and to not store and relay unconfirmed transactions via the mempool. Setting the value to 1 is not great for the health of the network as such, but does allow you to run a node with a bandwidth reduction of upto 88% https://bitcointalk.org/index.php?topic=1377345.0

mempoolexpiry is a time in hours that transactions are held in memory for.
maxmempool is a value in megabytes of how much RAM to use.
maxorphantx is the no of orphan transactions to store in the mempool.
maxuploadtarget is a target upload in MB over a 24 hour period, the default is 0 which is unlimited so the minimum we suggest would be 6 x 24 = 144x1 = 144 so that you at least relay each block once.

Using listen=0 can also help to reduce bandwidth consumption.