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Re: [rtl] maximum frequency for periodic tasks
> This will be done on a Pentium 200MMX, at the moment I am using a P166
> for some testing. The documentation states the maximum achievable
> frequency would be approximately 150us (6666Hz) on a P120.
Before I get to your question, could you please give the link to the
specific part of the documentation where you saw this info? I would
like to find this info, but I could not find it just now when I looked
for it.
> Does anybody have any experience whether I can work safely with tasks at
> frequencies up to 25kHz, or will I get in trouble sooner or later (will
> harddisk/network work reliably)?
I don't have personal experience, but, Paolo Mantegazza
<mantegazza@aero.polimi.it> sent me the following note about 2 months ago
in reply to my question about how fast RTLinux can go:
"I can only answer this. Take care that it depends on what you want to do
in a task In my opinion the official release can run the 1 task
square-wave test at about 50 Khz. The problem of the official release is
the oneshot programming that requires more that 10 us. And now just a bit
of advertising. My variant can run the same task at 130 Khz with periodic
timing and 100 Khz with oneshot timing. All the above figures are with a
233 Mhz P2. My variant is based on the official release but I've changed
the clocking and tasking my way. So far the only person using my variant
in production is Daniele. You can ask him for an opinion. His measures
say that a full way switch, i.e. from the clock interrupt to a new rt task
running is about 5 us, with fp support working. I think that without fp it
is about 1 us less. As far as I know it is the only rtl implementation
that allows to chose between periodic and oneshot timers on a single cpu
pc. As you know you'll have to use the official new alpha 1.2a release to
get the same services."
Maybe Paolo or Daniele can answer it.
Good luck,
Dave
------------------------------------------------------------
David Christini, Ph.D. dchristi@mail.med.cornell.edu
http://cardiodyn.med.cornell.edu/~dchristi
Division of Cardiology, Cornell University Medical College
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