File synapse.sysconfig of Package matrix-synapse

# Synapse's architecture is quite RAM hungry currently - we deliberately
# cache a lot of recent room data and metadata in RAM in order to speed up
# common requests.  We'll improve this in future, but for now the easiest
# way to either reduce the RAM usage (at the risk of slowing things down)
# is to set the almost-undocumented ``SYNAPSE_CACHE_FACTOR`` environment
# variable.  Roughly speaking, a SYNAPSE_CACHE_FACTOR of 1.0 will max out
# at around 3-4GB of resident memory - this is what we currently run the
# on.  The default setting is currently 0.1, which is probably
# around a ~700MB footprint.  You can dial it down further to 0.02 if
# desired, which targets roughly ~512MB.  Conversely you can dial it up if
# you need performance for lots of users and have a box with a lot of RAM.