I upgrade when I decide my computer sucks. That's why I got rid of the Phenom II x3 and went with this powerhouse. It's pretty bad when a CPU bottlenecks a GTX 560Ti. Next I'll be upgrading from this 560Ti and will try to sell it on Ebay.
Every 1-2 years, or whenever i'm bored with my current setup. I don't upgrade for anything in particular anyway, i actually enjoy researching, buying, fitting and testing new hardware, could never do it just to play games, hasn't been a game developed yet that is worth spending hundreds of £'s on.
All the time ... when i see something worth the change, i do it... I was in overclocking so... GPU, well, depend but the upgrade have take me a bit more lately, as i allways buy the high end, paired in SLI or CFX.... The 5870 are certainly the gpu's i have keep the longer.
cpu: 3-4years or more if its strong enough (can keep above 40-50fps), i got this quad in late 2008 and i think it will be fine until IB-E (Q4 2012 or early 2013). gpu: 2years or so, usually i wait for refreshed next generation. In this case Kepler refresh or SI refresh, i just got this 570 not so long ago
When I have cash and when there is a need for upgrade. Add something every year, but cpu and gpu upgrade in 1-3 years.
Whenever I need to. I would probally still be rocking a Core 2 Duo E6600 if it was not bottlenecking my GTX470 and my future plans of going SLI.
I buy it all at once for a complete upgrade, even case, but this time I got my new case early and will upgrade everything else....mouse included, next year. Likely after windows 8 release.
I upgrade in this Order.. Battlefield 1942 Geforce 3 Pentium 4 2.0 GHZ Battlefield Vietnam FX5600, FX5900XT Pentium 4 2.0 GHZ Battlefield 2 6600GT, 7900GS, 8800GTS AMD 64, OPTY dual core 939 2.6 GHZ Battlefield 3 560GTX PhenomII Quad 3.6 GHZ
Depends on needs or budget. Although im about due for an upgrade, however my system is still adequate for the time being. Mainly because im stuck playing classic games from 2005 +1 on the Q6600
I don't really have a cycle, I upgrade parts as I see fit. I tend to buy at least a new gfx card or cpu every year though. This way I still get to sell parts for a decent price and recuperate some of the money.
My upgrade cycle is pretty clear, platform upgrade every about 5 years (earlier if need be). Other upgrades in a tick-tock fashion between work and gaming. I just upgraded my GPU and my motherboard can't support further upgrades, so the next thing on the docket is a platform upgrade due in Q2 2012. Projection calls for a P77 or Z78 chipset motherboard and an Ivy Bridge CPU. deltatux
CPU every 3 years (but often every 2). GPU every 2 years (more often every year). So impulse buys and need for something new to play with seem to interfere with the logic of my upgrade cycles.
Whenever my PC starts struggling, or as of late whenever my mobo dies. But as little as possible. I buy a little bit at a time, which works out to be a new system every 3 years...