[Vincent Ferrari]

http://www.appleinsider.com/article..._speed_ups.html

"When clock speeds are identical between systems, such as with the new low-end 2.66GHz iMac and a mid-range predecessor from last year, the difference in test scores becomes almost unnoticeable, coming down to 11 points in the case of the two all-in-ones. Even the 2.93GHz iMac, which replaces a 2.8GHz model, has only a 189-point advantage -- or about a 5 percent speed difference that directly maps to the higher clock rate."

Apple Insider does note that there's probably a big leap in video performance due to the new Nvidia chips inside, but in operations where there's a lot of CPU and memory throughput, there isn't that big of a difference between the current model iMacs and the new ones.  That's food for thought if you're planning on purchasing one of the newer systems.  A caveat, of course, is that we don't know how much this will change when Snow Leopard rolls around, so choose your weapon carefully!

[Vincent Ferrari]

http://www.appleinsider.com/article..._speed_ups.html

"When clock speeds are identical between systems, such as with the new low-end 2.66GHz iMac and a mid-range predecessor from last year, the difference in test scores becomes almost unnoticeable, coming down to 11 points in the case of the two all-in-ones. Even the 2.93GHz iMac, which replaces a 2.8GHz model, has only a 189-point advantage -- or about a 5 percent speed difference that directly maps to the higher clock rate."

Apple Insider does note that there's probably a big leap in video performance due to the new Nvidia chips inside, but in operations where there's a lot of CPU and memory throughput, there isn't that big of a difference between the current model iMacs and the new ones.  That's food for thought if you're planning on purchasing one of the newer systems.  A caveat, of course, is that we don't know how much this will change when Snow Leopard rolls around, so choose your weapon carefully!

[doogald]

If you bought an iMac as recently as last year, I think that you'd be foolish to think of replacing it right now. If the reason is something to do with Snow Leopard, you might as well wait until 10.6 is actually here; by then the specs may have been bumped again at the same price anyway.

[Vincent Ferrari]

Originally Posted by doogald

If you bought an iMac as recently as last year, I think that you'd be foolish to think of replacing it right now. If the reason is something to do with Snow Leopard, you might as well wait until 10.6 is actually here; by then the specs may have been bumped again at the same price anyway.

Agreed. I don't see anything compelling for recent upgraders. If your old iMac is long in the tooth, though, these aren't bad machines.