Idk. I just upgrade every two years. But, if your computer is laggy and slow, then it is time to upgrade.

Since I usually "over buy" when I replace my PC, the trigger to replace the current one, is when I can no longer meaningfully upgrade it. My last PC lasted 8 years because of this and I had upgraded RAM and CPUs (dual CPU workstation motherboard) a couple of times. Since I never buy a notebook, this is a trivial solution; if you want/need portability, this idea will rarely work.
The bigger problem can be that the purchase will be higher as the components to allow upgrades over a longer period of time means that you end up purchasing the higher capability/leading edge parts, but not always the highest performing components. For me, this results in a functional computer for a long term, but won't give the best performance at any time, but performance isn't my primary need; longevity and consistency is more important to me. I also don't use Windows except in VMs, so it's much easier to have a long running OS that doesn't require re-installation regularly.

I'm very "thrifty" with my computers. So I'll essentially use them until they break or can no longer be useful. So I decide based purely on need.

That said, I recently re-built my main computer to be "ready for the next 10 years". I don't plan on upgrading it, or getting a new one during that time, unless something breaks.

Laptops are a little different, as the "usefulness" of them change depending on the circumstances. Right now I'm using a Pixelbook, which will be replaced in 2024 due to losing security patch support. I'll probably still use it, but will probably replace it with either the next version of Pixelbook (if there is one) or a lean portable laptop which I'll plan to use for the foreseeable future. Its purpose is portability, stability and web-access.

Since I work with computers daily, I try to not to "budget" too much with my purchases. I got all higher end spec stuff for my desktop, and have the highest spec'ed Pixelbook. The Pixelbook replacement will be high spec as well as I want it to last as long as possible.

I don't do anything crazy with my purchases, and keep things straight forward and powerful. My desktop has an all in one liquid cooling for the CPU, lots of fans, a solid founders graphics card, and solid SSDs. Nothing fancy, all higher end, but not ultra top of the line either. It should be fine if I take care of it and should be easy to repair and maintain. It's not picture worthy, I disabled all the flashy LEDs, and got a functional case.

I have a stack of older machines that can still run if needed, but they just wont cut it compared to my desktop in terms of power, and wont be as stable, and portable as my Pixelbook. This trend should hold out in 2024 when I get my next "5 year" laptop, or however it can last depending on the specs.

When it starts acting up. It's a tool, it gets to work until it can't anymore. Latest case are mysterious PSU failures and burnt memory sectors.

When my previous work seems ended, I know this is time to buy a computer, my previous PC is 4GB RAM desktop PC. But my previous work I used a MacBook Pro 2019 13 inch 8GB RAM + 256GB SSD, touch bar. That computer is give huge benefit to may daily work, just intell processor a littlebit too noisy. So When I faced the issue of Apple next models is 14, 16 inch coming out without touch bar I know which is my prefered model: 2020 MacBook pro 13 inc M1 chip 16GB RAM 512GB SSD ... so this year I went to another workplace, and I rent that model, and it is awesome:

• M1 processor - 8+ hour battery life without use of CPU fan.
• light power use - save the planet.
• Touch Bar - my personal favourite because easy change between ES - HU language, screenshot, voice level, clock,, emoji selection 🙀 ... an so more.
• MacOS which is fare better than windows or linux, with tons of useful program, even I can record what is going a single click. Also just press FN twice and I can use dictation.
• best terminal : iterm2
• easy migration from my older one brew list to brew install ...
• I can write code near anywhere so it is really portable device.
• touch pad is also best ( forget mouse ), gestures like fast task swipe.

I usually keep them a good 10 years.

Motherboard died 2 months ago, just before reaching 11 years of loyal services. I had to get a new processor and RAM but I kept everything else. Total Cost: under 500€.

In this discussion, just curious after reading comments, like I am thinking to buy MacBook Air, and now am using windows 10 with WSL.

Is it good to buy one? I majorly work on back-end using PHP JavaScript tailwind etc.,

In India, MacBook price are way higher, Andi it's been around more than 4 years am using the same laptop, but installed a SSD for speed.

Should I go for MacBook Air or try iMac or some dos based system.

My priority is that the computer must wait for me to throw more commands/actions instead me waiting the computer to finish whatever it's doing.

Of course there are actions that I'll need to wait for it to finish but you can have an idea.

With this in mind I overpower my builds and, as I use desktop computer I can change or upgrade any hardware piece at any time.

Current build:

• Ryzen 5800X (liquid cooled)
• NZXT N7 B550
• 4x8 (32Gb) RAM DDR4 4400MHz
• RTX 3080 ti FE
• Sabrent Rocket nvme 1Tb PCIe-4
• A couple of SanDisk Sata SSD 1TB 3D.

I'm probably not changing a thing in a couple of years or more.

For the laptop it's different, as for me is something to use few times when in need to travel, I've a Huawei Matebook D14 AMD 2019 (Ryzen 3500u, 8Gb RAM, 256 Gb nvme).
If I'm in need for a better laptop in a future or if I'd need a laptop instead a desktop, I'd probably pick the matebook D16 with a Ruzen 5800H and 16Gb of RAM, which is a beast for coding and also serves for casual gaming.

It's just about covering the needs on the best efficient way.

As extra, I don't recommend a Mac/Macbook unless you are about to code iOS Apps. Rosetta does not support all compilers and libraries in most platforms and you may got a hard time coding with it.

Every 5 years and depending if I have the budget