When should I upgrade or replace my computer?

“To buy or not to buy, that is the question.”

(What can I tell you - I was an English major :D)

Is it time to upgrade your computer or should you buy a new one? And the answer is everyone’s favorite:  “It depends!” For starters, you should know that Apple computers generally last longer than Windows computers. In my experience, a Windows computer typically lasts about 3 years—with desktops usually holding out a bit longer than laptops. With an Apple computer,  you can generally expect 5 to 8 years of service. But let’s hear details from Microsoft. Here is their breakdown of (laptop) hardware life:

• Processor:  While central processing units (CPUs) can last up to a decade, they may become obsolete as software requirements increase.

• Hard drives:  Moving parts in traditional hard drives are prone to failure; they typically last 3-5 years. Solid-state drives (SSDs), without moving parts, tend to last longer but can still degrade with extensive write cycles.

• Battery:  Laptop batteries degrade with each charge cycle, usually warranting replacement or affecting portability after 2-4 years.

• RAM:  Random access memory (RAM) can last a long time but is susceptible to failure due to power surges or overheating.

• Motherboards: Capacitors and other components on a motherboard can fail due to heat and cheap construction, often becoming the limiting factor in your laptop’s lifespan.

Source: Microsoft

When should you consider an upgrade?

I think the most helpful suggestion from Microsoft on this site is the following. I feel it applies just as well to Apple devices:

When your computer starts to frequently crash, takes longer to perform tasks, or can't run the latest software efficiently, it's time to start looking for a new one.

Apple estimates that the average lifespan for their devices is 4 years. 

Source:  Frankenstein Computer and Networking

However, this does not correspond with  my experience with Macs, so I asked Google Gemini AI for more detail and here is what AI provided:

In answer to the question, “How does Apple conduct its Product Greenhouse Gas Life Cycle Assessment?,” Apple notes that after years of study it assumes the lifespan of a OS X or tvOS device (i.e. an iMac, MacBook or Apple TV) is roughly four years.

While Apple doesn't publish a document explicitly titled "When You Should Buy a New Computer," they do have an official, definitive support policy that draws the line for when a machine is considered too old. Apple categorizes older hardware into two official buckets: Vintage and Obsolete. This policy acts as Apple's official signal that it is time to start looking for a replacement.

1. The "Vintage" Window (5 to 7 Years)

According to Apple’s official service policy, a product is considered vintage when Apple stopped distributing it for sale more than 5 years ago, but less than 7 years ago.

• What it means for you: Your computer will still work, but getting it fixed becomes a gamble. Apple and Apple Authorized Service Providers will only perform repairs or replace parts subject to parts availability.

2. The "Obsolete" Line (7+ Years)

A product crosses into obsolete status when Apple stopped distributing it for sale more than 7 years ago.

• What it means for you: Apple completely discontinues all hardware service for obsolete products.Service providers cannot order official parts for them at all. If the computer breaks, Apple's official stance is that it can no longer be serviced.

In the end, how your computer is behaving will guide you.  Is it very slow?  Can it no longer get updates? Is it unable to run programs you need?  Then, Hamlet would say it is time “to buy.”