Cisco ASA 5550 series adaptive security appliance
This is a bit of an upgrade from the Cisco ASA 5520 I tore down in this video:
• Cisco Adaptive Security Appliance ASA...
The processor in this was a Pentium 4 3.0GHz 1MB l2 800MHz FSB SL8JZ. With a total of 4GB of DDR memory there really isn't much higher you could go unless this supported 2GB sticks. This was probably quite the firewall back in its day.