While moving from one nest to another (we're lemmings here; RP it a bit) I realized I still have all computers I ever bought or assembled, except for those that literally broke beyond any hope of repair.
Some are no longer used daily but all work and being on a point in life where everything and anything in the nest needs to have a purpose or a function, led me think what actually renders a computer useless or truly obsolete.
I was made even more aware of this, as I'm in the market to assemble a new machine and I'm seeing used ones - 3 or 4 years old - being sold at what can be considered store price, with specs capable of running newly released games.
Meanwhile, I'm looking at two LGA 775 motherboards I have and considering how hard can I push it before it spontaneously combusts to make any use of it, even if only a type writer.
So, per the title, what makes a computer obsolete or simply unusable to you?
Addition
So I felt necessary to update the post and list the main reasons surfacing for rendering a machine obsolete/unusable
overall and consumption vs computational power
Linux rule!
For me, it's the hardware failure. If it's damaged enough to be uncomfortable to use, it's done. Similarly, if it can't run a modern browser decently.
I just ditched a >10yo laptop that I used as a server. The display was off most of the time, and the battery offered some energy backup. Its last months I couldn't even use the power button, had to take the mobo battery out and connect it without the battery in order to turn it on. Touchpad wasn't working either. OS hard drive was failing but that was replaced. I'm sure the thing works fine but I can't find the right flex cables to connect the power button and touchpad to the mobo. Guess it's going to trash soon.