Pro Good for static content and high traffic sites
Nginx is particularly good at hosting static content. Here is a test that was run sending 100b of static data to Nginx running on an ASUS U30JC laptop. The above graph also shows Nginx's ability to handle concurrency. Nginx's performance stayed quite steady even as the concurrent connections increased, which makes it a good option for people looking to run a larger site and are serving primarily static content.
Nginx offers a pretty lightweight server. The minimum recommended hardware is a 2 core CPU, 4GB RAM, and a 500GB HDD. With that you can expect a server to handle 90,000 requests per second and a 9Gbps throughput.
You can read more about the technical specs of Nginx here.
Pro Handles massive amounts of connections
Nginx was tested to handle a max of 261,033 concurrent connections per second (CPS) using 32 cores. The test itself was done on a machine with 2x Intel Xeon E5 v3 @ 2.3GHz (CPU), 2x Intel XL710 40 GbE QSFP+ (Network), and 16GB of RAM, running on Ubuntu Linux 14.04.1.
You can see more details about the test here.