"Invisible" <voi### [at] devnull> wrote in message
news:4886e543@news.povray.org...

>
> > Anyay, I only have access to the big servers til friday. After that the
> > biggest machine I'll be able to test on is my new (still in
construction)
> > quad code, 4GB desktop.
>
> Aww... If it makes you feel any better, *my* desktop box has 256 MB RAM
> and only one core. (AthlonXP 1700 I think...)

Work or home? The quad core I'm talking about is my home machine. The
desktops at work aren't very impressive either

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"somebody" <x### [at] ycom> wrote in message news:4886e09d@news.povray.org...

> It of course won't happen, but an ideally balanced system should show 100%
> utilization in all active subsystems when performing non-interactive tasks
> like launching an application, for instance. Low CPU usage can be a
symptom
> of poor disk caching.

75% is about the max that you want to see sustained for long periods. More
than that means there's too much contention. That's more applicable to
servers than desktops, and by sustained I mean 10 min or more.

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On Wed, 23 Jul 2008 01:42:08 -0600, somebody wrote:

> "Patrick Elliott" <sel### [at] rraznet> wrote in message
> 
>>until you closed the last window. And that doesn't even mention that
>>fact that, for most tasks, Linux never went above 1-2% processor
>>utilization, where hard tasks could take 24%, like playing video, and on
>>a machine without a dedicated video system for handling stuff, while
>>just opening the application would spike Windows at 70%+.
> 
> Are you saying Linux wastes 98 - 99% of the CPU? Typical 1-2% CPU
> utilization and a cap at 24% tells me that that particular system or
> Linux has a severe bottleneck somewhere else.
> 
> It of course won't happen, but an ideally balanced system should show
> 100% utilization in all active subsystems when performing
> non-interactive tasks like launching an application, for instance. Low
> CPU usage can be a symptom of poor disk caching.

No, I'd say that it's because Linux is a bit more efficient in its use of 
the processor.  I wouldn't expect to see 100% utilization unless I was 
actually running a highly intensive application like POV-Ray that 
actually needed the CPU.  Launching a program is kid's stuff - no reason 
for that to suck 100% of the CPU.

Jim

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>> Aww... If it makes you feel any better, *my* desktop box has 256 MB RAM
>> and only one core. (AthlonXP 1700 I think...)
> 
> Work or home? The quad core I'm talking about is my home machine. The
> desktops at work aren't very impressive either

Oh, work, obviously. ;-)

At home, I have an Athlon64 X2 4200+ 2.2 GHz with 3 GB RAM. >:-D

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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In article <4886e09d@news.povray.org>, x### [at] ycom says...
> "Patrick Elliott" <sel### [at] rraznet> wrote in message
> 
> >until you closed the last window. And that doesn't even mention that
> >fact that, for most tasks, Linux never went above 1-2% processor
> >utilization, where hard tasks could take 24%, like playing video, and on
> >a machine without a dedicated video system for handling stuff, while
> >just opening the application would spike Windows at 70%+.
> 
> Are you saying Linux wastes 98 - 99% of the CPU? Typical 1-2% CPU
> utilization and a cap at 24% tells me that that particular system or Linu
x
> has a severe bottleneck somewhere else.
> 
> It of course won't happen, but an ideally balanced system should show 100
%
> utilization in all active subsystems when performing non-interactive task
s
> like launching an application, for instance. Low CPU usage can be a sympt
om
> of poor disk caching.
> 
No, that was 1% - 24% utilization when running the "basic" tasks that 
the average person does, like editing a document, or a spreedsheet. No 
way in hell I want my OS using 70%, let alone 100% of the CPU just to 
fracking edit a letter. ;)

-- 
void main () {

    if version = "Vista" {
      call slow_by_half();
      call DRM_everything();
    }
    call functional_code();
  }
  else
    call crash_windows();
}

<A HREF='http://www.daz3d.com/index.php?refid=16130551'>Get 3D Models,
 
3D Content, and 3D Software at DAZ3D!</A>

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> No, I'd say that it's because Linux is a bit more efficient in its use of
> the processor.  I wouldn't expect to see 100% utilization unless I was
> actually running a highly intensive application like POV-Ray that
> actually needed the CPU.  Launching a program is kid's stuff - no reason
> for that to suck 100% of the CPU.

Of course there is, if a certain amount of code needs to be executed by the 
CPU to "launch" the program, I want my OS to use 100% CPU until it's done. 
Whether that takes 0.01ms or 1 second, it should still use 100% CPU until 
it's done.  What on Earth is the reason not to?

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On Thu, 24 Jul 2008 09:21:31 +0200, scott wrote:

>> No, I'd say that it's because Linux is a bit more efficient in its use
>> of the processor.  I wouldn't expect to see 100% utilization unless I
>> was actually running a highly intensive application like POV-Ray that
>> actually needed the CPU.  Launching a program is kid's stuff - no
>> reason for that to suck 100% of the CPU.
> 
> Of course there is, if a certain amount of code needs to be executed by
> the CPU to "launch" the program, I want my OS to use 100% CPU until it's
> done. Whether that takes 0.01ms or 1 second, it should still use 100%
> CPU until it's done.  What on Earth is the reason not to?

If that program takes 100% of the CPU, then *nothing* else gets any CPU - 
other applications, the OS, etc.  Those things need resources, too.

Jim

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Jim Henderson <nos### [at] nospamcom> wrote:
> If that program takes 100% of the CPU, then *nothing* else gets any CPU - 
> other applications, the OS, etc.  Those things need resources, too.

  That's not how pre-emptive multitasking works.

  You don't need "free CPU time" for task switching to work. It's not like
a program using 100% of CPU time would mean the OS has lost control.

  100% CPU time simply means that the OS is giving all the CPU time to
that process because nothing else needs the CPU. There's no need to keep
the CPU idle for no reason if only one process requests CPU time.

  CPUs support this thing called a clock interrupt. This means that at
certain intervals (the interval can be set up by the OS) a clock circuit
sends a signal to the CPU, which causes the CPU to stop whatever it was
doing and jump to a predefined location (which also can be set up by
the OS). This predefined location is usually the task manager of the OS.

  The task manager has a list of processes, categorized by their priority,
whether they are idle or not (there exist OS system calls which a process
can call to make itself idle) and other details.

  If only one process is non-idle, the task manager simply resumes the
execution of that process. The effective result of this is that that process
gets 100% of CPU time (well, more precisely something like 99.9999% because
the task manager takes that 0.0001% to check the list of processes).

  It's impossible for a process to block a pre-emptive OS completely.
When the clock signal interrupts the CPU, the CPU just stops executing
that process, period. There's no way around it. When that happens, the
OS is free to do whatever it wants. If another process has just started,
the OS can share CPU time with it, no problem. If they have equal priorities
and both are CPU-intensive, they will get 50% each.

  Some people really do seem to have some kind of confusion with this.
They believe that taking 100% of CPU time means that no CPU time is left
for the OS to perform task switching. This is just not how CPUs and
pre-emptive multitasking works. The OS is not hindered in any way.

-- 
                                                          - Warp

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>> Of course there is, if a certain amount of code needs to be executed by
>> the CPU to "launch" the program, I want my OS to use 100% CPU until it's
>> done. Whether that takes 0.01ms or 1 second, it should still use 100%
>> CPU until it's done.  What on Earth is the reason not to?
>
> If that program takes 100% of the CPU, then *nothing* else gets any CPU -
> other applications, the OS, etc.  Those things need resources, too.

I meant the CPU being at 100% during the program loading, not that 
particular program using 100% all for itself.  Of course I assume the OS can 
do important things, but still the CPU should not be below 100% while I am 
waiting for a program to load (assuming it's CPU bound).  That would be just 
wasted time.

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On Thu, 24 Jul 2008 11:20:54 -0400, Warp wrote:

>   That's not how pre-emptive multitasking works.

Yes, I am aware of how pre-emptive vs. non-preemptive multitasking 
works.  Been working with OSes for many, many years.

And that kinda is my point to Scott.

Jim

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