I think it would be more important for you to spend the extra $200 on ram. The 250 mg that comes with the new iMacs is just not enough for GPO if you want to load in more than just a couple of instruments. OSX is a real memory hog. ItÕs a shame that Apple gives you so little ram. If you can possibly upgrade to 1 or 2 g. ram you wonÕt be sorry.
Good luck with your new iMac and let us know how you like it. They look like such cool machines.
Since we're dealing with the same exact CPU running at two different speeds, let's assume that the difference in performance is proportional to the difference in MHz. So, for example, if you could run 16 reverb effects on the 1.6 GHz, then you would be able to run 18 reverbs on the 1.8. (The bus speed on the 1.8 model is also faster than the 1.6, so that may or may not screw up my reasoning.) So yes, there is a difference, but it's not earth-shattering.
However, for your setup which includes GPO and some other software samplers, your money may be better spent on upgrading the RAM. These iMacs ship with only 256 MB default, which is just not enough to run all of those programs you mentioned. But also bare in mind that while you can add more RAM to either machine, the 1.6 is probably not upgradeable to 1.8. If money is an issue, go with slower speed/more RAM.
But also bare in mind that while you can add more RAM to either machine, the 1.6 is probably not upgradeable to 1.8. If money is an issue, go with slower speed/more RAM.
I'm no expert, but wouldn't be better to go for all the processing speed you can, as adding RAM is relatively inexpensive and painless?
If the money issue is only a matter of waiting a little bit for a next paycheck or something, and you could afford the RAM upgrade soon, I'd go for CPU. But if you'll have to live with your pre-installed RAM amount for weeks or months, then I'd go for the RAM.