Just a few things.
First, SSD's have taken a HUGE price plunge in the last year. 7 months ago I paid $130 for a 500gb Samsung 860 EVO SATA SSD. Less than a month ago I paid $130 for a 1 TB Samsung 860 EVO SATA SSD (actually, I bought 3 of them, 2 for the RAID 0 array in my desktop and 1 for my 2nd hd in my gaming laptop). So using a small SSD and a regular old-school hard drive no longer makes sense.
In fact, I'm going to make a declaration for the record right here.
Now that you can buy a 1 TB SSD for less than $150, the age of the mechanical hard drive is OFFICIALLY OVER. There is no longer any reason to stoop to using such antiquated technology. (I've officially been 100% SSD on every rig I own for over a year now - death to the conventional hard drive).
The appropriate amount of RAM for a gaming computer is 16 gig in 2018. If you're going to be streaming, the upgrade to 32 gig can make sense.
The i5 4670 is a 4th Gen cpu. We're on Gen 9 now. Just saying.
The 780 Ti is also several generations old. Fine for running old school games, if that's what you play. For more modern usage, the GTX 10 series (1080, 1070, ect) and new RTX 20 series (2070, 2080, ect) are where you really want to be. For modern games. And ESPECIALLY beyond 1080p resolutions.
Your system is a good gaming rig, the only problem is it's a good gaming rig in 2014. We're nearly 5 years on from that now.