Spanky Deluxe said:
Do we actually know for sure if Rosetta is opimised for multi-core environments? Emulation software rarely is. If its not then non Universal binary applications should run the same speed on Core Solo machines as Core Duo machines.
There are some fundamental misunderstandings here.
First of all, just nitpicking: You don't optimise for multi-core environments, you optimise for multi-processor environments. It doesn't matter one bit whether you have one chip with two cores or two chips with a single core each.
More important: Rosetta is not an emulator. Rosetta is a code translator. When you start a PowerPC application, Rosetta will translate all the code into x86 code, and then its job is done: You now have an x86 application. If the PowerPC application was multi-processor aware, then the translated x86 application is multi-processor aware, and if the PowerPC application wasn't multi-processor aware, then the translated x86 application won't be multiprocessor aware.
Emulators like Virtual PC work completely different. They emulate a different computer. An emulator can decide whether it wants to emulate a single processor computer or a multi processor computer. Since emulating a multi processor computer is difficult, they don't do it - it would usually be pointless because emulating a dual processor computer would take twice as long. On the other hand, multiple processors are of very little use if you try to emulate a single processor computer.
Third, you forget that you can run multiple applications simultaneously on a Macintosh. Even if one application doesn't run any faster because it uses a single processor only, that means on a dual processor system you still have another processor available that can do other tasks and can run other applications at full speed.
Fourth: There will never be a Macintosh with a Core Solo processor. Google for "Intel price list" and read for yourself why.
