Here's an interesting post I found in news:comp.os.vxworks:
Excerpts from netnews.comp.os.vxworks: 12-Nov-97 VxWorks vs NT by "Rahul
Chopra"@nt.com
> I am working on the VoIP initiative here. Wanted to know if anyone had
> done any comparative analysis between NT and VxWorks.
We're actually going to be examining real-time issues under NT
and VxWorks in a course we're doing next semester. Here's some
preliminary things:
1) NT: big. Need RAM, disk. VxWorks: small. Use what you need.
for your application.
2) NT: bad predictability. VxWorks: good predictability.
3) NT: Win32, GUI stuff. VxWorks: can be done with add-ons ($).
4) NT: not been to Mars. VxWorks: been to Mars.
5) NT: limited priorities, at mercy of device drivers.
Big priority inversion problems.
VxWorks: 256 priorities, device drivers can be properly
assigned priorities, no priority inversion problems
(uses priority inheritance protocol).
6) NT: lots of device driver support from manufacturers.
As in almost all of 'em.
VxWorks: not so good. Still a lot of device driver support
though.
7) NT: supports a few processors (x86, PPC, Alpha). Mostly
for PC-class machines.
VxWorks: supports a lot of different architectures.
Not really intended for PC-class machines, works
on VME chassis, PCI, ISA, others. Can be used
on PC-class machines (which is what we'll be doing).
If you are specifically interested in using NT for a real-time
project in an embedded system, then I would suggest you use VxWorks
instead.
If you're interested in some real-time applications co-existing
with your mail, word processor, etc. then NT is the way to go.
If you want an embedded application with graphical interfaces,
this is a toughy. VxWorks + 3rd party (Willows' Win32,
RasterGraphics' SDL, et al.) can be used to do most graphical things
pretty well. NT still has Win32, etc. support.
Hope this helps.
Note: it's very hard to do head-to-head comparisons, as you
generally need (1) the same hardware, and (2) the same application
mixture. Since NT and VxWorks are so different, (2) is usually
the hard one.
Knowing a little bit about how NT works internally, however, I
think that VxWorks would probably win most of the performance
battles.
If you throw in the real-time extensions for NT, this is another
kettle of fish. They do improve the predictability and "badness"
of NT; however, they don't solve all of the problems.
-- Kevin |
