Universal Applications
One of the problems with switching from the PowerPC RISC architecture to Intel meant that applications would need to be rewritten. To help speed up the process of transition, Apple developed Rosetta. This is an application that runs inside of the OS X operating system and dynamically translates code from older PowerPC software to run under the Intel hardware. Newer applications that will run natively under the OS are called Universal Applications.
While this system works seamlessly, there is a performance loss when running non-Universal Applications. Apple notes that programs running under Rosetta on the Intel based Macs will be as fast as the older PowerPC systems. They do not however say how much performance is lost when running under Rosetta compare to a Universal program. Since not all applications have been ported over to the new platform yet, some of my tests had to be done with non-Universal programs. I will make notes to when I used such programs in the individual tests.
File Systems
While the tests are using the same hardware, the software applications are very different. One of these differences that can impact the performance of the hard drive is the file systems that each of the operating systems use. Windows XP uses NTFS while Mac OS X uses HPFS+. Each of these file systems handle data in different ways. So, even with similar applications, the data access could cause fluctuations in the performance.
