# "All SRX100 Services Gateways have a built-in DDR memory of 1 GB. The SRX100 Services Gateway Low Memory devices can utilize a maximum of 512 MB of DDR memory. To utilize 1 GB of DDR memory, you must upgrade your device to an SRX100 Services Gateway High Memory version by installing the memory upgrade license" http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/concept/services-gateway-srx100-software-upgrade.html #