My preview window has started lagging really badly (even with the absolute worst preview settings), it was absolutely fine a few days ago, I've tried all the 'fixes' online and nothing improves it even a little bit. I've just noticed that during editing my CPU usage is 100% which I suspect is the problem? My CPU is an i7-7700k overclocked to 5GHz, so why on Earth is the usage so high?!
Here's some of my spec for reference:
OS: Microsoft Windows 10 Home
Mobo: ASUS Z270 TUF Mark 1
CPU: Intel i7-7700k @ 5.0GHz
CPU Cooler: NZXT Kraken X62
RAM: 16GB Corsair Dominator Platinum @ 3000MHz
GPU: EVGA 1080ti SC2 Hybrid
Case: Phanteks Enthoo Pro Tempered Glass
Fans: Corsair 140ML Pro
PSU: Corsair RM850i
OS SSD: Samsung M.2 960 EVO NVMe 500GB
Editing SSD: Samsung 840 EVO 250GB
Storage HDD: Seagate 2TB