news:apong7$6dc$1@inn.qnx.com...
Thanks Kevin for the yet another interesting link. I never heard nameRealtime doesn't mean "real-fast" and it can apply to a lot more than just
device control. Douglas Jensen has some interesting things to say on the
subject. See http://www.real-time.org/preview/introduction.htm
Douglas Jensen, but I agree with his point. Also I've read some articles
about real-time at QSSL website. I remember one of them was really
scientific like... and probably real-time for me it's something what's
called hard real-time. Ok. Where I said "real-fast"? For example, take a
look at Dedicated System's report QNX vs WinCE... and, for example, at such
important parameter as interrupt latency. What do you see? WinCE _sometimes_
in ten times slower than QNX. So, you're yelloing it's not real-time, it's
not predictable... It's true for equal boards. Then take the board ten times
faster with WinCE. What do you see? It's mainly faster then you need, but
worst case is good for you. In many cases, you have limited time to do a
task, but you don't care if task is calculated faster. Mostly important for
real-time is the maximal time which you need to spend for calculation in
order to not be flooded by input data stream. And second important parameter
for real-time is the delay between input data and well calculated output
data, because the data might be not actual (expired data). So, real-time is
not "real-fast". It's "real-predictable_fast"... IMHO.
Also, I know about excellent system architecture of QNX, about lots of
problems concerning all another OS... It's not a start of such discussion, I
hope.
Thanks everybody,
Eduard.
Kevin
"ed1k" <ed1k@nobody.fools.ca> wrote in message
news:apnrhg$691$1@inn.qnx.com...
"Kevin Stallard" <kevin@ffflyingrobots.com> wrote in message
news:apnjiq$rir$1@inn.qnx.com...
Hmmm...how did I miss that....they are talking about embedded linux,
nothing
about real-time there....
Thanks Kevin. Very interesting picture. Funny to compare next/current
ratio
for different OSes... FreeBSD is a leader and QNX isn't last oneAnd
real-time... what's real-time now? nobody care of real-time because
there
are lots of cheap and fast CPU now... but embedded it's still
something...
Cheers,
Eduard.