Just because you 'can' upgrade the CPU in X86 boxes doesn't mean that any system manufacturers will respect your warrantee if you do so.
If your talking software support, I think it depends on the upgrade maker. There are people running G3/4 upgrade cards in beige Macs and running OSX with no problem (but with less speed, natch)
Think of it this way, it's not like upgrades come out at some staggering pace. You certainly don't want to upgrade a machine in the first year of service, and reasonably, if you have some Applecare you won't want to untill AFTER 3 years have expired.
At that point you might find some cost effective upgrades (depending on how much the market has changed) and, realistically, one processor upgrade is all you can expect to make to a machine.
The upgrade manufacturers are pretty careful about this, and though it takes them some time, once they make a card, it functions no differently than an Apple daughtercard. They've even resorted to using Apple ROMS (Pismo upgrade, I think?) so that any OS couldn't tell the difference.
People who ran into problems were the iMac video upgraders, but I think that has more to do withthe death of 3Dfx (no drivers after that, hence no OSX) But unlike a video card the CPU must be supported in the first place, and that makes a it a less risky prospect (albeit a slow and sometimes expensive one)
Comments
Just because you 'can' upgrade the CPU in X86 boxes doesn't mean that any system manufacturers will respect your warrantee if you do so.
If your talking software support, I think it depends on the upgrade maker. There are people running G3/4 upgrade cards in beige Macs and running OSX with no problem (but with less speed, natch)
Think of it this way, it's not like upgrades come out at some staggering pace. You certainly don't want to upgrade a machine in the first year of service, and reasonably, if you have some Applecare you won't want to untill AFTER 3 years have expired.
At that point you might find some cost effective upgrades (depending on how much the market has changed) and, realistically, one processor upgrade is all you can expect to make to a machine.
The upgrade manufacturers are pretty careful about this, and though it takes them some time, once they make a card, it functions no differently than an Apple daughtercard. They've even resorted to using Apple ROMS (Pismo upgrade, I think?) so that any OS couldn't tell the difference.
People who ran into problems were the iMac video upgraders, but I think that has more to do withthe death of 3Dfx (no drivers after that, hence no OSX) But unlike a video card the CPU must be supported in the first place, and that makes a it a less risky prospect (albeit a slow and sometimes expensive one)