Third monitor plugged in lags computer in fullscreen borderless - are my specs too weak?

[mikeybimley]

The Problem: I have a dual monitor setup (HDMI from monitor to DP in PC) paired with a TV that runs at the same resolution (1920x1080p) and refresh rate (60Hz) connected HDMI-HDMI. The TV display duplicates my primary monitor's display, as I play games and then duplicate the display so I can play from my bed or have people watch in my room.

I have been experiencing an issue with particularly Call of Duty: Modern Warfare (most graphically demanding game I've played in a while; this issue might apply to other games) in which running the game in windowed-borderless results in frequent stutters dipping <40 FPS. If I play the game in windowed mode however, with the windows border at the top and black borders on the sides, I experience constant 60 FPS with no issues. If I unplug my duplicated-display TV, then I can play the game easily at 60 FPS in windowed-borderless.

My question is; is duplicating my primary display to my TV too much for my specs? Or is it a strange interaction with the TV (I am going to try a monitor from my friend as soon as I can), or is it something else like a mis-configured TV messing things up?

Specs

• OS: Windows 10 Home 64-bit (10.0, Build 18363)
• MOBO: MSI B350M MORTAR ARCTIC Micro ATX AM4 Motherboard
• Memory: Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000
• GPU: EVGA GeForce GTX 1060 6GB
• CPU: AMD Ryzen 5 1600 Six-Core Processor 3.2GHz
• PSU: Corsair Professional 1050W 80+ Gold Certified Semi-modular ATX
• Storage:
  • SSD, SSD, HDD, HDD, NVME SSD
  • Call of Duty was previously installed on my 5200rpm HDD, but earlier today I moved it to my NVME SSD and am still experiencing this problem.

BIOS Version: American Megatrends Inc. A.I0, 1/22/2019 (SMBIOS Version = 2.8)

• there is a bios update available but I am hesitant to install, as I've never done it before

 

A note; I have never overclocked any of my components. Should nothing work by 2/29 I will be reinstalling Modern Warfare to make the most of my data cap, and I will report back if that helps anything.

And another note: there have been reported issues with Windows Insider builds and Modern Warfare that cause similar problems to what I am describing, but I am not on a Windows Insider build.

Thank you for any help you can offer
Please let me know if there is any additional information I can provide.