fretful wrote:
Which of the following two scenarios is faster, given that all other factors would be the same:
There are other factors which you haven't mentioned (doesn't matter if they're the same or not, between the 2 configs) which will affect whether or not you actually measure much performance difference, but...
fretful wrote:
One disk accessed twiced, once at each edge (inner and outer) OR
Two disks simultaneously accessed once each.
From all my experience on performance investigations, I have never seen two I/Os to one disk (especially with a seek between them), be faster than one I/O to each of two disks (since these could be done in parallel) - i.e. the latter is typically faster. However, there are other factors about the exact usage, which might make the performance difference minimal.
fretful wrote:
The reason for this query is I want to know if it will speed-up my PC if the OS is on one drive and the applications are on another?
Although using 2 disks, as you describe above, has the
potential for some PC operations to be faster, I could construct some tests which would show minimal useful improvement and other tests which would show significant improvement. In other words - YMMV.

Since this forum isn't dedicated to PC performance & configuration, then this may not be the best place for you to ask your question. However I/O performance (on *nix-based systems) is something I've worked on for many years, so with the limited info available, I've given you some general info to answer your question.
