From: db3l@ans.net (David Bolen)
Subject: Re: OS/2 vs NT features list, Revision 1.5
Date: Fri, 4 Sep 1992 13:54:01 GMT
Organization: Advanced Network & Services, Inc. - Elmsford, NY
Followup-To: comp.os.os2.advocacy,comp.os.ms-windows.advocacy

Ok - guess I'll throw a few cents in...

In article <1992Sep3.234501.28636@hellgate.utah.edu> brian%jaguar.cs.utah.edu@cs.utah.edu (Brian Sturgill) writes:

> Can be configured with less features to use less memory than NT.
>	 If you add OS/2 2.0's memory requirements for the
>	 base package + TCP/IP base + MM + LAN Server Entry you get:
>	 6 + 1 + 1 + 3 = 11 megs.  NT currently requires 12 and is
>	 targeted to use 8 megs.  Thus I content neither has
>	 a real edge in memory usage when counting relevant add-ons.

It seems to me that if you are going to include a point in the "OS/2 has this
NT doesn't" section, and then basically negate it with some comments that it's
just asking to be complained about.  How about having a separate section for
areas that are not yet clear benefits to either system, but that might or
might not be?

For my comments on your comments.. the point is "can be configured with less
features", and you then compare it to NT by adding all sorts of features and
"counting relevant add-ons".  Isn't the whole point of this item that I get to
pick what is relevant to me?  If I don't want TCP/IP or MM or Lan Server I can
fit into 6MB right?  Doesn't that exactly agree with the title of this item?

Just wondering...

>#	Generic wait on multiple events/semaphores of different types.
>	 This feature helps prevent deadlocks.  Consider the classic
>	 deadlock example: Two processes, P1 and P2, both want
>	 to access tape drives A and B.  P1 locks A and waits for
>	 B, P2 locks B and waits for A. Deadlock.
>	 With the generic wait facility you say wake me when
>	 I have both A and B.  This mechanism prevents many
>	 deadlock problems.  Just to clarify, it's quite possible
>	 to do without this facility; it just makes things
>	 easier.

Since the subject is rather "generic" :-), could you be more explicit here?
It seems from your example that this is exactly what OS/2's MuxWait semaphores
would be used for, as they allow you to wait for multiple resources to become
free or multiple events to occur simultaneously...

If you mean strictly at a filesystem or device level do you imply not using
semaphores at all, but that an application somehow notifies NT first of all
the devices it will eventually want?  Does this also work if two applications
enter the same deadlock situation via two file locks?

> Automatic stack expansion.
>	 OS/2 2.0 does not (in the general case) have dynamic stack

I guess I agree with the topic in general (being one of those who posted about
it, but see next paragraph), but to be a little more accurate, don't you think
this should say something like "OS/2 2.0 does not in all cases ...".  I mean,
actually, in the "general" case it does - it's only thread 1 that doesn't -
every other thread does.

Also - does this really belong anymore in the section of NT has OS/2 doesn't?
OS/2 does have the feature, just not in all situations.  Perhaps it could fit
better in the "not a clear win" section I mention above.  After all, any OS/2
application can use stack expansion if it wants, and for example, the EMX
stuff gives it free (well, a little wasted memory) to any application, even
for thread 1.  So at most the advantage would be that it requires less effort
under NT, not that it isn't available.

> Global VM/File Buffer Cache.
>	 This is a common feature in most modern operating
>	 systems.  It apparently makes disk consistency
>	 easier to manage.

My only comment about this is that I'd be careful that by putting it in this
section without anything in the OS/2 section, it can sound like OS/2 doesn't
provide caching.  It may not provide exactly the same sort of caching as
NT, so that could be a point, but I wouldn't want to imply that the caching
itself is something OS/2 doesn't have.

> Dynamic loadable/unloadable file system and device drivers.

Similar to my previous comment - having this here and nothing in the OS/2
section can lead to believing OS/2 has nothing in this area.  OS/2 does have
dynamically (at boot time) installable filesystems, so perhaps some commentary
here could indicate that the important part of this feature is the possibility
of unloading and reloading file system and device drivers (providing that is
what you meant - with a command line command I can unload and reload the
drivers).

> Good _documented_ debug hooks.

How is this different than the _documented_ DosDebug interface under OS/2?

>#	NT can generically use more than 16 megs of memory.
>	 On ISA machines that don't support DMA above
>	 the 16 meg line OS/2 only uses the memory above
>	 16 megs as a form of fast swap.

(This is an aside - how does NT deal with this case - disable DMA entirely,
 or just keep buffers down in low memory for the purposes of DMA?)

>!	Has seamless support for 16-bit Windows apps on XGA and 8514 displays.
>	 Someone said that OS/2 2.0 has this now... but I thought
>	 otherwise.  Does the shipping version of OS/2 2.0 come
>	 with seamless XGA support? (I'm certain it doesn't for
>	 the 8514.)

I don't think seamless XGA/8514 is shipping yet.

>OS/2 LAN Server 2.0 Advanced Package (Not available for OS/2 2.0 yet)
> (Includes features of Entry Package above.)

Just to be clear - you can use 2.0 Lan Requester clients with an Advanced
OS/2 Lan Server.  It's just the server that has to be on OS/2 1.3.  So
this is usable by 2.0 users today.
--
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