Why does a new laptop lag?

Question

AMD

Good afternoon, I bought a new laptop Acer Aspire 3 A315-21G-97TR for study, office tasks, etc. Games are not interested.
Specifications:
CPU: AMD A9-9420e RADEON R5, 5 Compute CORES 2C+3G 1.80 GHz
RAM: 8.00 GB DDR4
Integrated graphics: AMD Radeon R5 Graphics
Discrete: AMD Radeon 520.
FullHD resolution.
When I started it, Windows was already installed, with all sorts of rubbish, the laptop slowed down a lot, the windows opened jerkily.
I formatted everything, installed my Windows 10, updated it, downloaded the drivers for a discrete video card, after a reboot, everything began to work well, the windows move smoothly, but the browser barely plows. All animations are jerky, windows open for a long time, scrolling is jerky. The CPU is always 100% loaded, according to the Task Manager. In AIDA, it shows a 60% load on one core and the same amount on the other. When you click on the browser, the load flies by 100%, when minimized, it drops to 10 - 30%.
I can’t come to terms with the idea that it’s the processor, because before that I had been sitting on a laptop with an Intel Core i3 4005U 1.7GHz, 4 GB of RAM for 4 years, so everything flies there. Could the problem be in high resolution?
What do you advise?

Answer 1

Because Acer, obviously.
In general, the matter may well be in the processor, more precisely in cooling and throttling. Well, the built-in video is also not very good. Perhaps the browser uses it. By the way, what browser is it? How many tabs and which ones? What's in memory?

Answer 2

Either marriage or hdd.