I have always wondered if having Windows and FSX on the same disk was a liability. From my experiences I would "guess" that Windows keeps its most used routines in memory. Thus calls for disk read or write do not cause Windows to go to the disk except for the customer's data. There may also be a hierarchy in terms of usage. That is, some routines are always eligible for roll-out while others stay unless there is a strong need for memory. A roll-out may be to Pagefile or simply erased and the next call for that routine requires acquisition from its original location. A slow process.So, given the need for FSX to constantly go to the disk for the next landclass texture, clouds or asset, the vast majority of disk activity is from FSX with little from Windows. Then FSX co-existing with Windows should not be a burden on performance.Another thought is that if you have a defrag program that sorts files by name, a disk with a 32mb cache versus16mb should allow for faster loading of FSX scenery items. Of course an SSD is ideal but I would be concerned about the wear factor due to FSX constsntly calling for new scenery data.Just some random thoughts....

Most of this is covered extensively in this very forum.FSX isn't going to hurt an SSD. Remember, it's constant writes that wear an SSD, but you shouldn't be worried about it anyway.Yes, Windows is always accessing the HD.