Minimal Linux system ideal for older computers
Minimal Linux system ideal for older computers
You're considering Linux for your slow laptop. It's running an AMD E1-2100 APU with Radeon HD Graphics and 4GB DDR3 RAM. The issue is high CPU usage when using apps, especially YouTube. You're looking for a stable distro that won't overheat or strain the system further.
Lubuntu is a great starting point, though your 2-core, 1GHZ system might feel a bit slow. Even a modest SSD can significantly improve performance. You have two choices: replace LXDE with bare Openbox for a minimal setup and install a taskbar yourself, which will run quickly and efficiently—compared to LXDE—or consider Puppy Linux, an extremely lightweight distro that’s lighter than Lubuntu but still functional.
Openbox is excellent. I run an older IBM T42 with Debian, and it functions perfectly. It may not be the strongest option, but it gets the task done since I mostly connect via SSH from a laptop. I suggest checking out https://www.bunsenlabs.org/ if you're just starting with Openbox. It's a solid introduction, and you can later switch to plain Debian and customize your settings.
I've seen that newer desktop setups tend to consume more RAM. Unless you're using a very weak integrated graphics card and applying heavy effects, they usually don't strain the CPU or GPU. The main concern is the apps you run. For instance, Firefox can be quite demanding on the processor. The operating system or distribution you choose won't change this situation. You might notice a slight improvement by switching to a smaller swap file, which frees up RAM for the system cache. Alternatively, if you're often running low on memory, a lighter desktop environment could help—just because of insufficient RAM. EDIT: I also realized your CPU speed is 1000MHz. In that case, a simpler desktop might actually be beneficial! Try it yourself.
I tend to favor xfce-based systems. Xubuntu is an option if you prefer that, or MATE (a bit more resource-intensive but excellent).