There's so much new computer hardware and gadgets coming out every month, it's like that brand new PC you bought last month with 48GB of RAM and 8 SSDs totalling 2 TB of memory with the latest and greatest sandy bridge core i7 (with eight physical cores) and 4 Nvidia cards is already obsolete :( Same thing is about to happen to all those 'hot new' smartphones and tablets that came out last winter. When is it the right time to upgrade computer hardware or buy a new gadget?
Well, computer hardware is constantly getting newer and better
The only solution to always having the best hardware is to keep buying. But I would say the best time to upgrade computer hardware is when it's relatively cheap
Say, there is a major sale. That would be when I would upgrade.
Might depend more on requirements.