Stretched or not stretched Moore's law still applies. Technology creeps up at a faster pace than our cash.
Every 6 months or so a new generation of CPUs comes on the market making the previous obsolete not to mention the one released two years ago.
Intel releases a new CPU generation once a year. Right now that seems the only relevant manufacturer for MacBooks. Two generations (i.e. two years) are quite noticeable in terms of speed, which should double.
Every new MBP release makes the previous model obsolete, just by definition of the word obsolete. But that's not a good measure for how long the laptop will last, which is what the OP asked. There is no clear answer to that, since it depends on how the laptop is used.
For me, a laptop lasts 3-4 years. After two years, I start to "want to have" new technology, although I don't really need it. After 3-4 years however, usually the following happens:
- the battery starts to get bad (about half of the original capacity/duration)
- memory upgrade would be required to keep up with OS and software updates
- more than one of the connectors is outdated
- laptop is missing new technology that has become mainstream
- new games don't even launch on the hardware
Besides the obvious memory/battery issues that can be fixed, in my case the old MBP has neither USB 3.0 nor thunderbolt, lacks support for some of the multitouch gestures, and has trouble with "standard" tasks like full HD video playing and scrolling through busy websites.
A new battery, memory upgrade and a SSD would have given it another year or two, but at that point I usually prefer to invest the money in a new machine.
For people that care about gaming 2 years is easily the cutoff after which new games don't run very well. Similarly, people who frequently use software that just require full computing power will benefit a lot from a 2 year upgrade.
Omg, I write too much!
