Yes if your not going to install a SSD you would be wasting your time and money, installing a 5400 RPM second hard drive. All you would get would be more storage space.
Installing a SSD and moving your OS and main programs will significantly increase your performance, Boot up time, program start up time. Anything that is hard drive intensive will see big performance Gains.
G752VY-DH72 Win 10 Pro
512 GB M.2 Samsung 960 Pro
1 TB Samsung 850 pro 2.5 format
980m GTX 4 GB
32GB DDR 4 Standard RAM
Z97 PRO WiFi I7 4790K
Windows 10 Pro
Z97 -A
Windows 10 Pro