Sounds like Windows is ruled out because you did a fresh install.
I prefer not to run CCleaner or Glary Utilities on a fresh install, especially the registry cleaner portion. I doubt removing a couple hundred empty registry entries on something that has thousands of entries, (especially when the registry is running on a lightning fast SSD, AND Microsoft recommends that you don’t,) will measurably affect performance. Same for temp file cleanup on an SSD fresh install. But that’s just me.
Here are just a few ideas, from easy to technical.
Temporarily disable your anti-virus protection and test again.
Verify all fans are working and heatsinks are clean.
If your overclocking anything, disable the overclock and re-test.
Verify trim is enabled on the SSD.
Almost every piece of electronics has built-in software that controls it. From the motherboards bios to the firmware on your Corsair SSD.
Verify that your GPU, motherboard, ssd / hdd’s and even the lowly cdrom drives have the latest version BIOs or firmware.
Verify you have the latest soundcard drivers.
Reset the motherboard, remove the battery and wait 30 seconds and short the reset pins. Restore factory defaults. You might need to re-setup the Ram timings if they don’t auto-detect.
If the video card drivers offer a clean install, pick that choice. Otherwise use the Display Driver Uninstaller app https://www.guru3d.com/files-details/display-driver-uninstaller-download.html
Look at the guides on tweakguides.com, especially the TweakGuides Tweaking Companion (TGTC).
EDIT**
Is anything unnecessary running in the Startup folder that could be shutdown.
Especially any program like CCleaner in the system tray which lurks around waiting to free up memory (not needed, you have 16 gigs) and prevent the dreaded cookie or temp file from lingering around longer than a nanosecond.
And Test on a fresh restart, before opening any other programs.