I have three types of customers.
1. People who mess their system up all the time, and replace the entire machine when they do (1-2 years).
2. People who mess their system up all the time, and replace every 2-3 times (~5 years)
3. People who don't mess up their system, have simple tasks to do, and do them the same way every time. I have a lot of these customers, but considering they only call for a new system every 8-12 years, it isn't a lot of business.
Edit: Strangely, each of these groups feels that their profile is "normal" and to be expected.
Don't know about the messing systems up part. Seems like mine seem to run, and run well, for a long time.
While I know some complain of server motherboard costs, as Splash used to point out, you usually don't have much in drivers to worry about, and, they generally just plug and play, provided you use the right components, ram, etc.
There does seem to be sort of a sweet spot on Xeons, where for around 250-300 dollars you get a processor that's competitive with the consumer processors, but, allows dual or more processors.
My experience with mine has been what, 9 years now!? and, they are still going strong.
Gaming rigs seem to be replaced more often, thanks to the new advances in Direct X, etc, and the components that are avaliable.
Not considered very often is the PCI bus speed, and the memory speed. It's usually so speed delayed by hard drives, that it hasn't been a factor. Flooding the bus doing data transfer was not something that happened often.
The biggest bottle neck in computer speed has been storage, but, that seems to be changing. With SSD's, you should now be able to raid them, and flood a slower bus.
I'm already planning a new machine. As soon as SSD's get down to a reasonable price per gigabyte ratio, I don't see anything that will keep the average consumer from Raid 0 boot setups. As I was typing this, I was wondering if SSD's end up giving the same ideal sweet spot of two drives raided that SCSI does, but, I doubt it. I noticed even through data transfer time was faster, access time was not as good when 4 or more drives are raided.
I don't think this will be the case with SSD's.
Windows 7 already is better by about 25% with SSD's then the released OS. That may change, but, it does indicate that the OS might now be a limit in how quickly data is processed.
So, with SSD's I see no reason an average consumer can't run a Raid 0 with at least 2, if not 4 or more, SSD's.
Here is one area a server motherboard is a better bet. When you buy one, you hope, and it's generally the case, that the chipsets used are the best around, and, you are going to get as fast a PCI bus as it's rated, or close, rather then some of the junk motherboard chips Apple or Dell have used, that aren't close to industry standard.
I guess my real question is how fast can SSD's go, and, at what point does the system bus become a limitation?
As for period of time between upgrades:
I've noticed my single processor gaming rig, and it's group of processors, are more likely to use more CPU then the dual Xeons doing the same task. In other words, I've only got one task that comes close to using 100% of the processors on the Xeons, and, rarely if ever find a multiple combination of tasks it can't do.
The same cannot be said of the Athlon 3200 setup.