Question Is it my cpu?

[JasonH81]

I just built this Refurbished Workstation PC from Newegg. Initially it was bought just to save my data from my dying laptop. I installed a free copy of Destiny 2 on it just for the fun of it, but fell in love with the 60fps gameplay. I was playing on low graphics settings. My monitor is only a 1080p monitor. I have no interest with higher resolutions. Initially I had the workstation GPU, but I upgraded to the just released EVGA GeForce GTX 1660 Ti XC Black Gaming, 6GB GDDR6, HDB Fan Graphics Card 06G-P4-1261-KR because I wanted better performance with better visuals. Most of the stages the game runs great at 60fps on Ultra settings. But there are some stages where the fps can drop down to 40-50fps. I can't figure out how to stabilize the fps. I believe the GPU should be sufficient. I believe that I can upgrade the CPU to an i7 3770. Please help me figure how to get better performance without downgrading visuals. Any help will also help with other games.

HP Z220 CMT
OS: Windows 10 Pro 64-bit Version: 17763.348
CPU: Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz
System Mem: 20GB
Mem 1: 2GB Samsung 1333MHz
Mem 2: 8GB 8502 1333MHz
Mem 3: 2GB Samsung 1333MHz
Mem 4: 8GB 8502 1333MHz
MoBo: 1790
BIOS: K51 v01.86
PSU: OEM 400W

GPU: NVIDIA GeForce GTX 1660Ti
Res: 1920 x 1080
Refresh rate: 60
Version: 25.21.14.1935 (3/1/2019)

SDD: Samsung 470 series 256GB SSD
HDD: Seagate BarraCuda Internal Hard Drive 2TB SATA 6Gb/s 64MB Cache 3.5-Inch (ST2000DM006)

 

[geofelt]

I think there was a windows update that damaged destiny 2 performance.
KB4482887

 

[JasonH81]

I think there was a windows update that damaged destiny 2 performance.
KB4482887

Oh, okay, but even other games the performace is a little spotty at times. I'm new to pc gaming so I don't feel comfortable OC the gpu, but that won't matter if the cpu is the bottleneck.