How to properly diagnose and find the causes of high hard drive usage?

Question

Video cards

After upgrading the video card, a constant 100% disk load.
Bought GYGABYTE 1060 GTX, 6GB. There was no 8-pin power supply, but there were two adapters: MOLEX * 2-> 8-pin and MOLEX / SATA-> 8-pin. PSU 550W.
Connected via molex. The system at that time was WIN10x64. The system started, I installed the drivers that were included.
At the stage of loading games, I felt a noticeable degradation in comparison with the old config (the video was 750i), launched the dispatcher and saw a constant peak disk load of 100%.
I remembered that dozens had problems with this: I turned off the update service, the search service, I tried a few more options from Google. It didn't get much easier.
I did chkdsk, defragmentation, looked at the smart screw, everything is within reason, there are no bads. I looked at the screw in Victoria, after in the utility from WD, order.
I updated all possible divers, even found an update for the BIOS and installed it.
Did not help.
I replaced the video card with the old one - the download is still 100%, it does not go away.
Rearranged win from another image - without result.
I tried to change the sata, power connectors, just wired me, it does not help. I took another screw on which there was already Windows, rolled back the drivers, installed the latest ones. Anyway, the disk with the system is loaded at 100%.
I've run out of ideas. Something wrong with mother (P7P55D)? Nutrition? Is the place cursed?
At the same time, the video itself works flawlessly, some games are loaded even with such a disk load, and then they work fine, not particularly interested in the disk. But most games crash at the loading stage.
P7P55D
i5-760 2.8
WDC WD10EADS / 1TB
ST31000524AS / 1TB
DDR3 2x2048 Corsair
DDR3 2x2048 Kingston
Gigabyte GTX 1060 6GB
PANGU s550W

Answer 1

WIndows 10 immediately after installation (especially if the image is old) launches all sorts of telemetry, updates, and more. Always just being patient, depending on the speed of the drive, it goes away in 40 minutes - 2 hours.
Well, I don’t recommend keeping the system without an SSD at all.