On Thu, 24 Jul 2008 17:21:35 +0200, scott wrote:

>>> 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.

Generally that isn't going to happen on modern processors, though, 
because the CPU hits 100% during computationally intensive periods, but 
internal clock speeds on CPUs these days tend to be *several times* the 
speed of even the bus to the CPU.

One of the reasons Intel entered the networking components market was 
because CPU utilization on their faster generations of processors was 
relatively low because of the speed differential between the time it took 
to process data and the time it took to get the data (or code, rather) to 
the processor to actually process things.

That may be what you're talking about here.  But this is why you won't 
see a CPU hit 100% during program load - the bus just isn't fast enough 
relative to the speed of the CPU.  Therefore, if you want to see 100% 
load on the CPU during a program load, you need a slower processor (until 
bus speeds catch up with CPU speeds, and that won't happen because of the 
physical distance the data has to travel on the bus to get to the CPU, 
where everything is nm apart instead of inches apart.

Jim

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