Posted 08 July 2010 - 08:51 AM
Numerous things can cause drive activity.
Windows writes to log files. Some applications maintain scratch files on the hard drive, and they'll be accessed at various times. The NTFS file system uses delayed writes, which can be committed to disk in batch writes if the system has been busy and the write queue reaches the maximum permitted delay.
Also, if there is no swapfile, and a larger memory allocation is requested than there is free memory available at the time, a module or modules that would otherwise have been paged to disk in the swapfile will have to be unloaded from memory. It will then be re-loaded from its original drive location when RAM becomes available again. (This is actually not as fast as being reloaded from the swapfile.)
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