I was wondering when people consider themselves to have a new PC. Technically I’ve had the same PC for close to 20 years now, but every part’s been upgraded several times over.
I figure everyone’s got a different mind about it. For me, I’d have to say when all of the big three—CPU, GPU, mobo—have completed a phase, my brain thinks of the previous setup as “the old PC”.
IMO, it’s when you replace the motherboard. It’s the real heart of the machine; without it, all your other parts ain’t doing shit. And since you can get by longer on the same motherboard while still leaving everything else to be upgraded, getting a new motherboard very often necessitates getting at least a new CPU and possibly RAM if you’re making a generational leap that requires a new socket type.
I always thought of the CPU as the beating heart and the MoBo as the vessel/body.
At the same time: upgrading CPU often requires a new MoBo too, so I guess they are bound together anyways.
For the original question I’d say CPU + MoBo swap is a new machine. GPU and RAM are upgrades.