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Le 14-11-14 10:41, Raiford, Michael a écrit :
> On 11/14/2014 5:59 AM, Le_Forgeron wrote:
>> Le 14/11/2014 00:36, Cousin Ricky a écrit :
>>> Le_Forgeron <jgr### [at] freefr> wrote:
>>>> On 13/11/2014 21:21, Cousin Ricky wrote:
>>>>> My hardware is a Dell Inspiron 17R with Intel Core i7 (8 cores).
>>>>
>>>> Isn't that 4 cores with HT ? (for povray, it would be worth 5 cores,
>>>> YMMV)
>>>
>>> I've seen "quad core" in literature not attached to this particular
>>> model, but
>>> in the POV-Ray statistics, there is a clear 8-to-1 ratio between CPU
>>> times and
>>> elapsed times. Does this mean that there are 2 CPUs in each core?
>>>
>>>
>> Sort of... there is two full set of registers in each core, allowing to
>> run two code in parallel... as long as they do not need the same
>> resources from the core.
>>
>> at 100% cpu like povray, yes there is a 8:1 ratio between cpu times and
>> wall-clock time. Yet, if the scheduler of the operating system is not
>> too bad, if you force povray to run on less threads (with -WT<number>
>> option), you can get some surprise like -WT8 is not twice faster that
>> -WT4.
>>
>> With good schedulers, povray -WT4 would run one thread per core, leaving
>> the other set of registers idle or used by something else.
>>
>>
>
> Yep. Pretty much that. I've noticed that my work computer (core i3, dual
> core) isn't quite as fast as my desktop PC (a Core2 Quad), even though
> it appears to have 4 cores to applications.
>
> I forget exactly what hyperthreading does, but it does give a bit of a
> boost to multi-threaded applications.
>
hyperthreading implement virtual core(s) on a CPU by having two sets of
registers. You have 1 true core that looks like there are 2. It makes it
faster to switch between threads.
Alain
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On 15-11-2014 19:07, Cousin Ricky wrote:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> LOL. I must say that where on/off is concerned, I do not have much
>> problem with +/-. It is those cases where there is no such thing and
>> where you can either use + or - for the same result that I begin to feel
>> itchy. It confuses the issue and as one does not always remember which
>> of those bloody settings can or cannot be switched... ;-)
>
> I just make a habit of using + unless I want to turn something off. That way
> the question never comes up.
>
Me too in fact. I have noted that explanations given here however, often
use -. I guess it is laziness: no need to use the SHIFT key while typing :-D
Thomas
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Thomas de Groot <tho### [at] degrootorg> wrote:
> On 15-11-2014 19:07, Cousin Ricky wrote:
> > I just make a habit of using + unless I want to turn something off. That way
> > the question never comes up.
>
> Me too in fact. I have noted that explanations given here however, often
> use -. I guess it is laziness: no need to use the SHIFT key while typing :-D
That's what the numeric keypad is for. :-)
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On 16-11-2014 16:23, Cousin Ricky wrote:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> On 15-11-2014 19:07, Cousin Ricky wrote:
>>> I just make a habit of using + unless I want to turn something off. That way
>>> the question never comes up.
>>
>> Me too in fact. I have noted that explanations given here however, often
>> use -. I guess it is laziness: no need to use the SHIFT key while typing :-D
>
> That's what the numeric keypad is for. :-)
>
>
[bangs head against table top]
Thomas
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"Cousin Ricky" <rickysttATyahooDOTcom> wrote:
> Thomas de Groot <tho### [at] degrootorg> wrote:
> > On 15-11-2014 19:07, Cousin Ricky wrote:
> > > I just make a habit of using + unless I want to turn something off. That way
> > > the question never comes up.
> >
> > Me too in fact. I have noted that explanations given here however, often
> > use -. I guess it is laziness: no need to use the SHIFT key while typing :-D
>
> That's what the numeric keypad is for. :-)
That requires moving my right hand all the way over to the keypad. No
self-respecting lazy person would do this.
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> "Cousin Ricky" <rickysttATyahooDOTcom> wrote:
>> Thomas de Groot <tho### [at] degrootorg> wrote:
>>> On 15-11-2014 19:07, Cousin Ricky wrote:
>>>> I just make a habit of using + unless I want to turn something off. That way
>>>> the question never comes up.
>>>
>>> Me too in fact. I have noted that explanations given here however, often
>>> use -. I guess it is laziness: no need to use the SHIFT key while typing :-D
>>
>> That's what the numeric keypad is for. :-)
>
> That requires moving my right hand all the way over to the keypad. No
> self-respecting lazy person would do this.
>
Type with one hand while keeping the other on the mouse. Then, it's just
a mather of hiting that big, double height, key with the thumb.
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"Cousin Ricky" <rickysttATyahooDOTcom> wrote:
> I must add that this was inspired by Richard Roseman's "Glass Panels":
Correction: That should be "Rosenman."
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