I can't give you a reference, though I am sure one could
find such
statistics easily enough with a well-composed
Google search. However, I can
give you anecdotal evidence
from personal experience. I develop a lot of
time-critical
multimedia software. Over the years I have made thousands of
measurements in the process of optimizing my software, and
thereby have gained
considerable practical experience with
the subject matter at
hand.
Though well-designed multimedia software can achieve
satisfactory
average throughput with file I/O, you
cannot count on timeliness
of any individual fetch or
store operation better than 50 ms, and should
develop
robustness into your application such that it will not fail
even if an
individual response is many times that. What I am
taking about here is the
buffering requirement for any audio
or video application.
For example,
professional audio applications ideally
should run on a real-time operating
system, and Windows is
anything but. The challenge in interfacing with an audio
device is to match the driver's real time buffer servicing
interrupt demands
to Window's unpredictable file I/O. If
this coupling is not correctly carried
out, one may find
tiny drop outs in a recording or such may be audible. It
takes years of experience and a lot of testing to design a
sound engine that
is impervious to Window's whims. In this
context, it is not uncommon at all to
seen Windows wander
off to attend to it's own priorities for hundreds of
milliseconds at a time, even with obvious sources of
interference from sources
like your antivirus and Windows
background file search disabled.
In
summary, it is clear that Windows does not give real-
time response a very high
priority in the list of trade
offs an OS has to make to serve the user. I have
no
experience with Linux, but I speculate that it would be
better. For one
thing, at a minimum, you don't even need an
antivirus on that platform, and
people often don't realize
how demanding antivirus software is of Window's
resources. A
very significant chunk of all the gains in efficiency as
hardware
has evolved over the years is consumed by antivirus
software alone. [ Reply to This | Parent | # ]
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