If you end up installing a hdd caddy, make sure you put the SSD in the main hard drive bay. Sometimes manufacturers cap optical drive SATA speeds to 1.5Gbps since optical drives dont need the extra bandwidth. While this is a huge inconvenience for the end user which only saves the company a couple pennies, at least your mechanial hdd won't be nearly as bandwidth starved on the slower line as an SSD would.
Main: i5-3570K, ASRock Z77 Pro4-M, Asus GTX660 TOP, 120 GB Vertex 3 Max IOPS, 2 TB Samsung EcoGreen F4, 8GB 1600MHz G.Skill @1.25V, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Samsung SSHD, 8GB 1866MHz G.Skill, Hand-Built Wood Case