bitcoin.conf

## Size of the database cache in megabytes; minimum 4.
## Lowering this lowers the amount of memory your node uses
dbcache=64

## Number of CPU cores to use for signature verification. The Raspberry Pi 2
## has four cores, so leaving one core free will help prevent your
## computer from slowing down too much when receiving blocks and
## transactions. If you want to verify faster (useful in mining and
## merchant settings), increase this number (up to the max 4 cores)
par=3

## Disable UPnP. This was the result of a vulnerability in previous
## versions of Bitcoin and it is suspected that additional
## vulnerabilities may remain. However, disabling this means that you
## will certainly need to manually allow incoming connections if you
## want them.
upnp=0

## Maximum number of connections, up to 125. If your node is using
## too much bandwidth, lowering this number and restating your node
## will probably help.
maxconnections=25

## Do not relay low fee transactions. This helps with keeping memory usage under
## control during periods of high congestion.
minrelaytxfee=0.0001

## Only use 1 thread for incoming RPC connections - saves memory again.
rpcthreads=1