Why are security appliances so popular with data center managers? Because they’re easier to install, configure, test, and often offer better performance than systems that you build yourself. Vendors’ architectural choices have profound implications for both the throughput that your appliance will handle and your ability to upgrade in response to new threats. Expect application-specific integrated circuits (ASICs) for perimeter firewall operations and XML processing, FPGAs for IDS and IPS, and even gateway antivirus, and custom processors for SSL VPN functions.”]
Source: https://www.csoonline.com/article/2118680/security-appliances-unwrapped.html