Date & Time: Jan 18th to present. I think Nvidia's latest driver is at fault.
Frequency: Constant

Bug issue: Borderless window mode with lower or mid-range frame caps cause the graphics card to run too slowly and results in sub-20 FPS rates. High frame caps work as expected, however.

Graphics Card: Nvidia GeForce GTX 3080

Steps:
1. Run borderless window mode
2. Use a frame cap of 1/2 or 1/4 refresh rate
3. Use "Reduce FPS when minimized."
4. Observe that the game runs at 10-20fps, and that the graphics card clock speed is a third or a half of what it should be. (using GPU-Z and discovered this. )

Solution:
If user wishes to run with frame cap
1.) Disable "Reduce FPS while minimized" option.
2.) Set the refresh rate of the monitor to the desired FPS cap. Example: Change your 144hz monitor to 120hz/90hz/72hz in windows and the Nvidia control panel.
3.) Run FPS cap at full refresh rate, not half or fourth.

If user wishes to leave their monitor refresh rate alone
1.) Leave cap off.
2.) Enable "Reduce FPS while minimized" so nobody accidentally cooks their GPU while tabbed out.



Expected cause: The 1/2 and 1/4 options are somehow failing to elicit the full attention/power/cooperation of the graphics card, as if the game is minimized when it isn't.

In the above dysfunctional scenarios I could verify through GPU-Z that the graphics card clockspeed was far too low. Less than half the full speed of the graphics card.

Expected result / thing that needs fixing: The 1/2 and 1/4 refresh rate options need to work. Setting a 72fps target shouldn't result in a 12-20fps result.



■ PC Specs

To obtain the system information, open the FFXIV launcher and select Config → System Information → Display.

-=-=-=-=- System Information -=-=-=-=-
SYSTEM_OS Windows 10 Pro 64-bit (6.2, Build 9200) (19041.vb_release.191206-1406)
SYSTEM_CPU AMD Ryzen 5 5600X 6-Core Processor (12 CPUs), ~3.7GHz
SYSTEM_CORE_NUM SYSTEM_CORE_LOGIC 12 SYSTEM_CORE_PHYSICS 6
SYSTEM_BIOS F14e
SYSTEM_LANGUAGE English (Regional Setting: English)
SYSTEM_MEMORY 32673.352MB
SYSTEM_VIRTUAL_MEMORY 134217727.875MB
SYSTEM_PAGE_FILE 37537.352MB
SYSTEM_STORAGE C:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 930.911GB SYSTEM_FREEDISC_SPACE 382.500GB
SYSTEM_STORAGE D:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 465.760GB SYSTEM_FREEDISC_SPACE 134.906GB
SYSTEM_STORAGE E:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 465.760GB SYSTEM_FREEDISC_SPACE 151.022GB
SYSTEM_STORAGE F:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 931.500GB SYSTEM_FREEDISC_SPACE 529.898GB
SYSTEM_STORAGE G:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 931.500GB SYSTEM_FREEDISC_SPACE 284.124GB
SYSTEM_STORAGE O:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 931.496GB SYSTEM_FREEDISC_SPACE 687.439GB
SYSTEM_STORAGE Z:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 465.745GB SYSTEM_FREEDISC_SPACE 386.326GB
SYSTEM_DIRECTX_VERSION DirectX 12
SYSTEM_GRAPHICS NVIDIA GeForce RTX 3080
SYSTEM_GRAPHICS_DEVICE \\.\DISPLAY1
SYSTEM_GRAPHICS_CHIP NVIDIA GeForce RTX 3080
SYSTEM_GRAPHICS_MAKER NVIDIA
SYSTEM_GRAPHICS_VRAM 10078.000 MB
SYSTEM_GRAPHICS_SHARED_VRAM 16336.676 MB
SYSTEM_GRAPHICS_DAC Integrated RAMDAC
SYSTEM_GRAPHICS_DISPLAY_MODE 1920 x 1080 (32 bit) (119Hz)
SYSTEM_GRAPHICS_DRIVER C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll
SYSTEM_GRAPHICS_DRIVER_VERSION 30.00.0015.1123
SYSTEM_GRAPHICS_DRIVER_DATE 1/9/2022 18:00:00
SYSTEM_GRAPHICS_DRIVER_LANGUAGE English
3.0
SYSTEM_GRAPHICS_PIXEL_SHADER 3.0
SYSTEM_GRAPHICS_VERTEX_TEXTURE SYSTEM_SUPPORT
SYSTEM_GRAPHICS NVIDIA GeForce RTX 3080
SYSTEM_GRAPHICS_DEVICE \\.\DISPLAY2
SYSTEM_GRAPHICS_CHIP NVIDIA GeForce RTX 3080
SYSTEM_GRAPHICS_MAKER NVIDIA
SYSTEM_GRAPHICS_VRAM 10078.000 MB
SYSTEM_GRAPHICS_SHARED_VRAM 16336.676 MB
SYSTEM_GRAPHICS_DAC Integrated RAMDAC
SYSTEM_GRAPHICS_DISPLAY_MODE 1920 x 1080 (32 bit) (60Hz)
SYSTEM_GRAPHICS_DRIVER C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_015fa42d67826549\nvldumdx.dll
SYSTEM_GRAPHICS_DRIVER_VERSION 30.00.0015.1123
SYSTEM_GRAPHICS_DRIVER_DATE 1/9/2022 18:00:00
SYSTEM_GRAPHICS_DRIVER_LANGUAGE English
3.0
SYSTEM_GRAPHICS_PIXEL_SHADER 3.0
SYSTEM_GRAPHICS_VERTEX_TEXTURE SYSTEM_SUPPORT
SYSTEM_SOUND Headphones (Oculus Virtual Audio Device)
SYSTEM_SOUND_DEVICE_ID {DBA137C5-F3FD-4D41-B20D-EA3D0862C682}
SYSTEM_SOUND_DEVICE_NAME oculusvad.sys
SYSTEM_SOUND_DRIVER_VERSION 13.3.46.740
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 2/10/2021 18:00:00
SYSTEM_SOUND Realtek Digital Output (Realtek(R) Audio)
SYSTEM_SOUND_DEVICE_ID {A03F905C-F0A8-404B-9B1F-B035B0D48F94}
SYSTEM_SOUND_DEVICE_NAME RTKVHD64.sys
SYSTEM_SOUND_DRIVER_VERSION 6.0.9225.1
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 8/16/2021 18:00:00
SYSTEM_SOUND Speakers (Realtek(R) Audio)
SYSTEM_SOUND_DEVICE_ID {57885FE5-4CF1-46C5-820B-1BD82C649F56}
SYSTEM_SOUND_DEVICE_NAME RTKVHD64.sys
SYSTEM_SOUND_DRIVER_VERSION 6.0.9225.1
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 8/16/2021 18:00:00
SYSTEM_SOUND Speakers (Samson Go Mic)
SYSTEM_SOUND_DEVICE_ID {52CD7296-67FA-4A57-B5DE-1DB2CAC6FE52}
SYSTEM_SOUND_DEVICE_NAME USBAUDIO.sys
SYSTEM_SOUND_DRIVER_VERSION 10.0.19041.1202
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 8/25/2021 18:00:00
SYSTEM_SOUND Speakers (Steam Streaming Microphone)
SYSTEM_SOUND_DEVICE_ID {59712C6A-AB06-418D-B3F0-8458D5641E2B}
SYSTEM_SOUND_DEVICE_NAME SteamStreamingMicrophone.sys
SYSTEM_SOUND_DRIVER_VERSION 8.33.15.17
SYSTEM_SOUND_DRIVER_LANGUAGE
SYSTEM_SOUND_DRIVER_DATE 7/27/2017 18:00:00
SYSTEM_SOUND Speakers (Steam Streaming Speakers)
SYSTEM_SOUND_DEVICE_ID {47D8D0FB-00E0-4F1C-A31D-ADCD5DB2F42F}
SYSTEM_SOUND_DEVICE_NAME SteamStreamingSpeakers.sys
SYSTEM_SOUND_DRIVER_VERSION 17.56.13.764
SYSTEM_SOUND_DRIVER_LANGUAGE
SYSTEM_SOUND_DRIVER_DATE 7/19/2017 18:00:00
SYSTEM_INPUT {6F1D2B60-D5A0-11CF-BFC7444553540000}
SYSTEM_INPUT_NAME Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 3 SYSTEM_GAMEPAD_BUTTON 8 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {6F1D2B61-D5A0-11CF-BFC7444553540000}
SYSTEM_INPUT_NAME Keyboard
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 128 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {34C2F810-2138-11EB-8001444553540000}
SYSTEM_INPUT_NAME ITE Device
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {16C2F4B0-683A-11EC-8001444553540000}
SYSTEM_INPUT_NAME USB DEVICE
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 3 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {64D26F80-BBCB-11EB-8005444553540000}
SYSTEM_INPUT_NAME XP-Pen Tablet
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 5 SYSTEM_GAMEPAD_BUTTON 5 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {16C2F4B0-683A-11EC-8002444553540000}
SYSTEM_INPUT_NAME USB DEVICE
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 8192 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {64D26F80-BBCB-11EB-8008444553540000}
SYSTEM_INPUT_NAME XP-Pen Tablet
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {504E3370-4883-11EB-8001444553540000}
SYSTEM_INPUT_NAME G502 HERO Gaming Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 652 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {504E8190-4883-11EB-8002444553540000}
SYSTEM_INPUT_NAME G502 HERO Gaming Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 3 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {0E68CFF0-BBCA-11EB-8001444553540000}
SYSTEM_INPUT_NAME ACD02
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {504E8190-4883-11EB-8003444553540000}
SYSTEM_INPUT_NAME G502 HERO Gaming Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {16C2F4B0-683A-11EC-8003444553540000}
SYSTEM_INPUT_NAME USB DEVICE
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {F04DF220-8DB1-11EB-8001444553540000}
SYSTEM_INPUT_NAME USB Receiver
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 767 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {504E8190-4883-11EB-8004444553540000}
SYSTEM_INPUT_NAME G502 HERO Gaming Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {F04E1930-8DB1-11EB-8002444553540000}
SYSTEM_INPUT_NAME USB Receiver
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 3 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {F04E1930-8DB1-11EB-8003444553540000}
SYSTEM_INPUT_NAME USB Receiver
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {DCE10680-81C4-11EB-8001444553540000}
SYSTEM_INPUT_NAME Samson Go Mic
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 3 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {34CDA670-2138-11EB-8007444553540000}
SYSTEM_INPUT_NAME ITE Device
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-


Similar report with another afflicted user: https://forum.square-enix.com/ffxiv/...gly-low-fps%29

Example image: https://imgur.com/a/dgGE8ak