About multitasking, what's best : AmigaOS, Linux, or Winblows XP ?

[Piru]

@Speelgoedmannetje

SCSI because it was better usable for multitasking purposes (or so I read somewhere).

At that point of history IDE HDDs and controllers were all PIO, that is polled by the CPU. Reading or writing something required full CPU attention. SCSI on the other hand was DMA, freeing the CPU for other tasks.

However, IDE soon gained DMA aswell. These days (with modern HW) it makes little difference from CPU usage perspective which you have. Certain specific ultra high speed applications might require SCSI still, otherwise SATA-II and RAID built with SATA devices has replaced SCSI pretty much.

[Speelgoedmannetje]

Ah, thanks for clarifying :-)
There was a kinda similar (off-topic) discussion about this in this thread.

[stopthegop]

Hmmm... maybe a hardware issue? I shut down errant processes all the time, and aside from the occasional momentary hang, it's fine. Come to think of it, I don't think I've had to reboot windows due to a (software) crash in years.

Congratulations.  You own the only reliable Wintel box on Planet Earth.  I'm not talking about just one box that I own, I'm talking about literally thousands of different servers and workstations that I've worked on.  I do Field support work (15+ yrs) for a very well know storage systems company -- robotic tape libraries, disk arrays, etc..  In my experience, when customers report hardware problems (tape drives not being recognized, LUN mapping problems, unable to initialize robotics, unknown path to host, storage unit unavailable, etc, etc, etc...).  I could go on for days..  But the problem is almost always software, in spite of what Microsoft or anyone else says.  My experience is mostly with Veritas (sorry, Symantec) NetBackup,  Legato, Tivoli TSM, Comvault, BackupExec, Amanda, and some non-public proprietary storage applications.  Netbackup on a lean unix box is the best of many bad choices (read: windoze/linux).  

[Tomas]

MacOS and Windows 3.x dont have multitasking at all. They only pretend so.

I think he meant Mac OSX...

[tonyvdb]

The big thing that the Amiga had and in a way still has over any windowz OS is that it can multi-task very smoothly and effectively. Yes modern day windowz machines have more raw horsepower but they need it to do multi-tasking as well as they do. Another member on here memtioned this in another thread but I have also done this, on the Amiga you can format more then one drive/partition at the same time. Try doing that on a PC. :-D
The Mac OS has done well in this department and is leaps ahead of the PC in this regards.

[Tomas]

Not true. Windows 3.1 did cooperative multitasking, and Windows95 did preemptive multitasking (like AmigaOS). Lousy deceptive marketing strategy it was of M$ to call Windows 3.1 just 'multitasking', suggesting it's being equal to any other multitasking OS.

No, win9x used cooperative multitasking, which was also the case with later version of classic mac os.

[SamuraiCrow]

Piru wrote:
In general, Windows scheduler works fine.

In one specific case, Windows' scheduler doesn't work fine and that's in the case of multiple processors/cores.  It just strips off the top priority tasks and assigns them to cores and lets the last core deal with all of the lesser tasks.

Of course AmigaOS doesn't support multiple processors yet but this is one vulnerability in XP.  Vista will probably be better but few would want to put up with the DRM contained in it. :lol:

[Speelgoedmannetje]

Tomas wrote:

Not true. Windows 3.1 did cooperative multitasking, and Windows95 did preemptive multitasking (like AmigaOS). Lousy deceptive marketing strategy it was of M$ to call Windows 3.1 just 'multitasking', suggesting it's being equal to any other multitasking OS.

No, win9x used cooperative multitasking, which was also the case with later version of classic mac os.

Then why can I play music, play a game and download something at the same time on my old pentium 200 with windows 95?

[Wain]

Just for clarity, windows 95/98 does indeed support pre-emptive multitasking.  However, it only uses the scheduler to make context switches if the running program supports pre-emptive multitasking as well.  So, windows 9x is more of a pre-emptive/cooperative hybrid.

My understanding is that this is for backward compatibility issues, but I may well be wrong, it has been years since I've bothered looking at any of this stuff.

I do know that in my years as a windows systems coder under 95-2000, never once did I have to directly initiate a context switch.

[Piru]

@Tomas

Windows 95 introduced preemptive multitasking to Windows family of OSes. Earlier Windows versions used co-operative multitasking.

See Wiki: Pre-emptive multitasking and Wiki: Co-operative multitasking.

[tonyvdb]

Then why can I play music, play a game and download something at the same time on my old pentium 200 with windows 95?

You may not notice but the download is not a steady stream nor will the game play full smooth frames as it will pause many times as other things are going on. Yes it is multi-tasking but its not "true" multi-tasking.

[Tomas]

Then why can I play music, play a game and download something at the same time on my old pentium 200 with windows 95?

You could do that on win3.1 as well. It just does not work as efficiently.

But i might be wrong... I read around and i find conflicting info, some say that win9x is cooperative while some says it has half implemented preemptive support. So i guess Wain is right..

[Piru]

@tonyvdb

You may not notice but the download is not a steady stream nor will the game play full smooth frames as it will pause many times as other things are going on. Yes it is multi-tasking but its not "true" multi-tasking.

Well by that definition AmigaOS isn't true multitasking either.

[Speelgoedmannetje]

Tomas wrote:

Then why can I play music, play a game and download something at the same time on my old pentium 200 with windows 95?

You could do that on win3.1 as well. It just does not work as efficiently.

Nope you can't. You can switch between programs, but they pause if they 'run' in background. Believe me, I tried :-)

[tonyvdb]

The one thing in windows 3.1 was if you ran more than one application that required the clock timing it would crash. I used a program on 3.1 that required it and had to ve very cautious not to open other programs I could open other windows but as soon as I ran a program it would lock up the entire computer and had to reboot.

[tonyvdb]

Piru wrote:
@tonyvdb

Yes it is multi-tasking but its not "true" multi-tasking.

Well by that definition AmigaOS isn't true multitasking either.

In a way your right but I'm sure you would agree that the Amiga will be far more efficient at it. And as I mentioned before try formating more then one drive at the same time on a PC