I wonder, is it worth it at all to put dual 2ghz into my current 1.42ghz dual FW800 G4 powermac?
If I see the Dual 1.8 on ebay that is.
As someone who has done exactly that, I can tell you that perspective is important here. "Upping" your 1.42 to 1.8 and expecting your MDD to suddenly act like a new Mac Pro will leave you sorely disappointed. By that I mean you have to remember that how fast a computer "feels" is a product of multiple factors of which CPU speed is only one. Bus speed, HDD access time, RAM all have a say in how it moves along.
Nothing will give an old computer a "shot in the arm" generally than to replace an old HDD with an SSD, since that's one of the bottlenecks that shows almost constantly. However, upgrading the CPU to 1.8 will make a serious improvement if you run processor-heavy / processor-dependent tasks like rendering video, managing gigantic spreadsheets, large Mp3 encodes etc.
Tasks that require a lot of computation will benefit most. Note: I was going to say "anything will benefit" but that may not always be true. The 7447 PPC chip, while clocked faster, has no level 3 cache and there may (stress
may because knowing for certain would require a
lot of serious testing) be more or less benefit for different tasks.
That said, while I did see a noticeable improvement going from 1.42 to 1.8, it was definitely
not as dramatic and as obvious as I would have liked considering the cost. But, when I do those kinds of things like say, repeated AAC or Mp3 test encodes, it's really nice to have.
