The drive htat will run slower is the slower drive when you boot from it. When running Windows from the sata drive you will seeing it run a little bir faster there due to the 7,200rpm not 7,000. But the main to remember is that Windows itself is one big application loaded into memory where the hard drive after loading is oblivious in Windows mind. That is running in memory.
A 8gb drive at this late date is actually better off for Linux or some other older version of Windows like 95 or 98. You won't be able to install too much there. With Vista you no longer have to worry about having a sata driver floppy made up for installing Windows on a sata drive. The updated installer already contains some generic form of drivers and readily asks which drive ide or sata to install to on the advanced users option. XP still needs to load those from a floppy.
