Without detailed information about your computer, storage, and footage you work with, it is all meaningless guesswork.
Gather your information and store it as your signature (see below.) It will always be there for others when you post.
FC7 is quite elderly, perhaps the same age as your computer, So the hardware is adequate for it. You do not say what version of Adobe product you are working with, but it may not run well on an older computer.
System:
Dell Precision T7600 (x2)
Win 7 64-bit
32GB RAM
Adobe CC 2017.1 (as of 8/2017)
256GB SSD system drive
4 internal media drives RAID 5
Typically cutting short form from UHD MP4, HD MP4, and HD P2 MXF.