Laptop: "It shouldn't slow down, but it slows down." Where is the problem?

Question

Windows

Good day. On the other resource did not receive a clear answer.
Given: An
old ultrabook:
i5 3317U
4 gb ram, 2 soldered on the motherboard, 2 inserted into the only slot
Factory 24 GB SSD (used for expresscache, currently disabled by software)
Smartbuy Ignition Plus SSD (instead of the stock 5400 rpm screw in minute)
GeForce 645M (1gb)
Windows 10 SL
Analogs - several machines with approximately similar characteristics.
Wild brakes in most of the programs used
Browser (I’ll clarify right away - the problem is definitely not the speed of the Internet):
Opening and loading some sites can take 30 seconds, on analogues - up to 15.
YouTube slows down every 5 seconds (fullhd, buffering goes as it should, beyond the current playback position). Often this happens on videos with a duration of five minutes or more.
I only play hearthstone, and if someone knows what's what, all the sagging happens immediately after opening tasks, friends list, etc. In the battle itself, there are no sagging and no brakes. On analogues, there are no sagging and "thoughtfulness" at all. By sagging I mean the same scenario:
I press the button, there is an animation, then everything freezes. If you do not touch anything, then everything itself sags in 7-10 seconds. If you try to click somewhere, a Windows message will appear stating that the application is not responding with a proposal to close it. If you ignore it, after the same 7-10 seconds it disappears and everything returns to normal. At the same time, at any time, I can minimize the game and the system will respond as usual.
At the same time, according to the dispatcher, about 60-75% of RAM is used, the CPU is loaded by 15-30%, the disk is almost never used, resource consumption is "normal", approximately like on analogues. The swap file is present. Performance is set to maximum.
What I tried:
insert a bar for 8 gigs. Almost nothing has changed
earlier with the hard drive, the problems appeared the same way, when I installed the ssd the system began to work faster
played with the size of the paging file
enabled / disabled expresscache enabled
/ disabled the factory ssd
testing the new ssd gives normal results.
Where to look, what could be the problem?
Thank you!

Answer 1

I would start with a gradual change of Windows, for a start I would put a seven, if everything is fine there, I would choose another assembly 10 if it is bad there then the problem is in the hardware

Answer 2

Is everything good with cooling? What is the temperature of the processor / vidyahi? Maybe you need to clean the radiator / check the thermal interface?