CPU usage fluctuation from low to high

[MurKMaideR]

Hi guys. I've scanned the internet in hopes of finding a solution before posting, but it appears that I'm at a loss.

Anyhow; I've had FPS dips in games for a while now. My system is a bit older but should be performing optimally well for what I'm using it for. I am playing Destiny 2 exclusively and have always gotten over 90fps with everything maxed out (PC specs at bottom). I have a 60Hz monitor so i try capping the framerate at 60 and get this overly noticeable tear that seams to stay linear and work its way up or down my display, I never get a "smooth" experience. The only way I have countered this (not 100%, mind you) is by uncapping the framerate. Now here's the weird part; I'm pulling 90fps on Ultra, with massive dips to 65 on occasion, which I expect from my hardware. When I turn on a frame cap of 60 or run v-sync my FPS will drop to 59 then bounce back to 60 continuously. This causes a worse experience than leaving it uncapped, but the playability is not ideal. I should be running this game like butter at 60fps. Even weirder yet, if i scale back my graphic settings to low and enable the 60 fps lock, I still get that little dip or stutter to 59 then back to 60. I noticed today that my CPU will go from 25% usage up to 50% then suddenly back to 20 or 25% when playing Destiny. I assume this is normal, as demand is required, but I want to be clear with my readers.

Here's what I've done before posting this;
Check that RAM is in dual-channel according to mobo manual and XMP is enabled.
Disabling HPET
Verified updates to Windows and Nvidia.
Slight, stable OC to graphics card.
Increased any values allowed in BIOS for non-K CPU to increase performance.
Set all power saving settings to max performance
Set all Nvidia control panel options to the best optimal performance.
Released over half of my HDD and defragmented.

I feel like after adding a slight boost to my graphics card and seeing no change in performance that I can assume it is my CPU. All temps under load are a cozy 60c and speaking of which, I reapplied MX4 about 9 months ago. Temps do get to 85c for both CPU and graphics card under stress test with stock coolers and average air flow.

I'm out of ideas and would love some feedback. Thanks everyone!

i5-4670 @ 3.4GHz
MSI GTX 970 White Tiger
16gb DDR3 @ 1600MHz
RM750 PSU

 

[MurKMaideR]

Update*
So after installing Malware Bytes and running a scan, I found that Advanced System Care 11 was being flagged. Also, I had over 8 "Bitcoin Miners." After uninstalling ASC11 and removing malware, I am seeing drastic improvement in both my games and computer responsiveness. I guess I should run Malware checks more often.

I hope this helps someone!