Wrong.
Go to AnandTech to see how the Nehalem Mac Pros use special Xeons without the Intel heat-spreader on top. They bind the bare cores directly to the cooling assemblies for a better thermal coupling.
Our IT department routinely replaces failed components in Dell towers, and has never had to replace a component in a Mac Pro over the same time period. One reason is that Apple uses very conservative designs -- they always use memory that is one step down from what the CPU can handle, for example. Gamers hate that, but it does extend the life of the components pretty dramatically. And anyway, LCDs are locked at 60 Hz, so Mac Pro is now a pretty damned good gaming platform as well.![]()
And you think Apple isn't using bargain basement components? I've already replaced the mobo and the battery in my MBP. Great components they purchased there with their stepped down tight integration. The other problem is that you're comparing against Dell and your stats are flawed. How many Dells do you control? How many macs?
I still have an old OCed Celeron machine running at a family members house. I don't even know how old it is now. I have an Athlon 64 machine running as a server next to me, again not sure how old.
I know the Apple lovers hate to admit it, but great machines that last a long time can be built by home builders and companies other than Apple - usually at much less cost.