I have an old single core puter using hyperthreading with XP.

If I got this right..
XP thinks it's got 2 CPU's. 
One thread will only use 50% of CPU mips.
So when I run spice, the CPU is only 1/2 working.
The other half is for whatever...email,browser,OS stuff etc.

I want spice to at full speed.
Is there a way to set XP such that only my spice app gets nearly full
CPU attention?
When the spice app is not running, the computer goes back to 50 50
hyperthreading.

Note: I do have the option in bios to disengage hyperthreading.
I might do that if hyperthreading is being a pita.


D from BC
myrealaddress(at)comic(dot)com
British Columbia
Canada

"D from BC" <m...@comic.com> schrieb im Newsbeitrag 
news:d...@4ax.com...
>I have an old single core puter using hyperthreading with XP.
>
> If I got this right..
> XP thinks it's got 2 CPU's.
> One thread will only use 50% of CPU mips.
> So when I run spice, the CPU is only 1/2 working.
> The other half is for whatever...email,browser,OS stuff etc.
>
> I want spice to at full speed.
> Is there a way to set XP such that only my spice app gets nearly full
> CPU attention?
> When the spice app is not running, the computer goes back to 50 50
> hyperthreading.
>
> Note: I do have the option in bios to disengage hyperthreading.
> I might do that if hyperthreading is being a pita.
>
>
> D from BC
> myrealaddress(at)comic(dot)com
> British Columbia
> Canada


Hello,

You can get what you asked for if you use the latest LTspiceIV.
It will stress all your CPU-cores to its limits. Let's see when the first
people will claim LTspice has burned their Quadcore-CPUs because
of  running long lasting simulation runs. :-)

None of  the other SPICE programs you can afford will use more
than one CPU-core.

Best regards,
Helmut

On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
<h...@t-online.de> wrote:

>"D from BC" <m...@comic.com> schrieb im Newsbeitrag 
>news:d...@4ax.com...
>>I have an old single core puter using hyperthreading with XP.
>>
>> If I got this right..
>> XP thinks it's got 2 CPU's.
>> One thread will only use 50% of CPU mips.
>> So when I run spice, the CPU is only 1/2 working.
>> The other half is for whatever...email,browser,OS stuff etc.
>>
>> I want spice to at full speed.
>> Is there a way to set XP such that only my spice app gets nearly full
>> CPU attention?
>> When the spice app is not running, the computer goes back to 50 50
>> hyperthreading.
>>
>> Note: I do have the option in bios to disengage hyperthreading.
>> I might do that if hyperthreading is being a pita.
>>
>>
>> D from BC
>> myrealaddress(at)comic(dot)com
>> British Columbia
>> Canada
>
>
>Hello,
>
>You can get what you asked for if you use the latest LTspiceIV.
>It will stress all your CPU-cores to its limits. Let's see when the first
>people will claim LTspice has burned their Quadcore-CPUs because
>of  running long lasting simulation runs. :-)
>
>None of  the other SPICE programs you can afford will use more
>than one CPU-core.
>
>Best regards,
>Helmut
>

Great!

I checked my LTspice version ..it's version 2.25d :( Ugh..
I'll get version 4.

Thanks


D from BC
myrealaddress(at)comic(dot)com
British Columbia
Canada

On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
<h...@t-online.de> wrote:

>"D from BC" <m...@comic.com> schrieb im Newsbeitrag 
>news:d...@4ax.com...
>>I have an old single core puter using hyperthreading with XP.
>>
>> If I got this right..
>> XP thinks it's got 2 CPU's.
>> One thread will only use 50% of CPU mips.
>> So when I run spice, the CPU is only 1/2 working.
>> The other half is for whatever...email,browser,OS stuff etc.
>>
>> I want spice to at full speed.
>> Is there a way to set XP such that only my spice app gets nearly full
>> CPU attention?
>> When the spice app is not running, the computer goes back to 50 50
>> hyperthreading.
>>
>> Note: I do have the option in bios to disengage hyperthreading.
>> I might do that if hyperthreading is being a pita.
>>
>>
>> D from BC
>> myrealaddress(at)comic(dot)com
>> British Columbia
>> Canada
>
>
>Hello,
>
>You can get what you asked for if you use the latest LTspiceIV.
>It will stress all your CPU-cores to its limits. Let's see when the first
>people will claim LTspice has burned their Quadcore-CPUs because
>of  running long lasting simulation runs. :-)
>
>None of  the other SPICE programs you can afford will use more
>than one CPU-core.
>
>Best regards,
>Helmut
>

I wonder if the other SPICE program writers are massively pissed about
LTspice being free.

Perhaps the LT president and LTspice writer get all 4 tires spiked a
little too often :P
But I don't think it's that gangsterlike in technology.. :)


D from BC
myrealaddress(at)comic(dot)com
British Columbia
Canada

On Tue, 20 Jan 2009 13:06:51 -0800, D from BC
<m...@comic.com> wrote:

>On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
><h...@t-online.de> wrote:
>
>>"D from BC" <m...@comic.com> schrieb im Newsbeitrag 
>>news:d...@4ax.com...
>>>I have an old single core puter using hyperthreading with XP.
>>>
>>> If I got this right..
>>> XP thinks it's got 2 CPU's.
>>> One thread will only use 50% of CPU mips.
>>> So when I run spice, the CPU is only 1/2 working.
>>> The other half is for whatever...email,browser,OS stuff etc.
>>>
>>> I want spice to at full speed.
>>> Is there a way to set XP such that only my spice app gets nearly full
>>> CPU attention?
>>> When the spice app is not running, the computer goes back to 50 50
>>> hyperthreading.
>>>
>>> Note: I do have the option in bios to disengage hyperthreading.
>>> I might do that if hyperthreading is being a pita.
>>>
>>>
>>> D from BC
>>> myrealaddress(at)comic(dot)com
>>> British Columbia
>>> Canada
>>
>>
>>Hello,
>>
>>You can get what you asked for if you use the latest LTspiceIV.
>>It will stress all your CPU-cores to its limits. Let's see when the first
>>people will claim LTspice has burned their Quadcore-CPUs because
>>of  running long lasting simulation runs. :-)
>>
>>None of  the other SPICE programs you can afford will use more
>>than one CPU-core.
>>
>>Best regards,
>>Helmut
>>
>
>Great!
>
>I checked my LTspice version ..it's version 2.25d :( Ugh..
>I'll get version 4.
>
>Thanks
>
>
>D from BC
>myrealaddress(at)comic(dot)com
>British Columbia
>Canada

I'm running LTspice4 now. Confirmed using help/about.
However. in Windows task manager scad3.exe is running.. huh...

Anyways.. 
My spice is not running faster and Windows Task Manager is only
showing CPU usage at 50%. iow...1 virtual core saturated.

I did spot the max treads option under the LTspice control panel.
It's set to 2.

I haven't noticed a change in speed. :(


D from BC
myrealaddress(at)comic(dot)com
British Columbia
Canada

On Jan 20, 1:28 pm, D from BC <myrealaddr...@comic.com> wrote:
> On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
>
>
>
> <helmutsennew...@t-online.de> wrote:
> >"D from BC" <myrealaddr...@comic.com> schrieb im Newsbeitrag
> >news:d...@4ax.com...
> >>I have an old single core puter using hyperthreading with XP.
>
> >> If I got this right..
> >> XP thinks it's got 2 CPU's.
> >> One thread will only use 50% of CPU mips.
> >> So when I run spice, the CPU is only 1/2 working.
> >> The other half is for whatever...email,browser,OS stuff etc.
>
> >> I want spice to at full speed.
> >> Is there a way to set XP such that only my spice app gets nearly full
> >> CPU attention?
> >> When the spice app is not running, the computer goes back to 50 50
> >> hyperthreading.
>
> >> Note: I do have the option in bios to disengage hyperthreading.
> >> I might do that if hyperthreading is being a pita.
>
> >> D from BC
> >> myrealaddress(at)comic(dot)com
> >> British Columbia
> >> Canada
>
> >Hello,
>
> >You can get what you asked for if you use the latest LTspiceIV.
> >It will stress all your CPU-cores to its limits. Let's see when the first
> >people will claim LTspice has burned their Quadcore-CPUs because
> >of  running long lasting simulation runs. :-)
>
> >None of  the other SPICE programs you can afford will use more
> >than one CPU-core.
>
> >Best regards,
> >Helmut
>
> I wonder if the other SPICE program writers are massively pissed about
> LTspice being free.

Not any more than than original free spice.  I just downloaded the
source, compiled and spiced.

On Tue, 20 Jan 2009 11:44:07 -0800, D from BC wrote:

> I have an old single core puter using hyperthreading with XP.
> 
> If I got this right..
> XP thinks it's got 2 CPU's. 
> One thread will only use 50% of CPU mips.
> So when I run spice, the CPU is only 1/2 working.
> The other half is for whatever...email,browser,OS stuff etc.

With hyperthreading, a single thread will use the entire CPU in the
absence of any competing threads (Windows reports that it's only 50%, but
it's lying; you can confirm this by running two processes on an
otherwise-idle system and noting that one process runs more slowly as the
other process consumes more CPU).

If you have a CPU with two full cores (Pentium-M), the only way that you
can utilise both cores is with multi-threaded code. You can't make the CPU
behave as a single, faster core.

In article <p...@4ax.com>, 
m...@comic.com says...
> On Tue, 20 Jan 2009 13:06:51 -0800, D from BC
> <m...@comic.com> wrote:
> 
> >On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
> ><h...@t-online.de> wrote:
> >
> >>"D from BC" <m...@comic.com> schrieb im Newsbeitrag 
> >>news:d...@4ax.com...
> >>>I have an old single core puter using hyperthreading with XP.
> >>>
> >>> If I got this right..
> >>> XP thinks it's got 2 CPU's.
> >>> One thread will only use 50% of CPU mips.
> >>> So when I run spice, the CPU is only 1/2 working.
> >>> The other half is for whatever...email,browser,OS stuff etc.
> >>>
> >>> I want spice to at full speed.
> >>> Is there a way to set XP such that only my spice app gets nearly full
> >>> CPU attention?
> >>> When the spice app is not running, the computer goes back to 50 50
> >>> hyperthreading.
> >>>
> >>> Note: I do have the option in bios to disengage hyperthreading.
> >>> I might do that if hyperthreading is being a pita.
> >>>
> >>>
> >>> D from BC
> >>> myrealaddress(at)comic(dot)com
> >>> British Columbia
> >>> Canada
> >>
> >>
> >>Hello,
> >>
> >>You can get what you asked for if you use the latest LTspiceIV.
> >>It will stress all your CPU-cores to its limits. Let's see when the first
> >>people will claim LTspice has burned their Quadcore-CPUs because
> >>of  running long lasting simulation runs. :-)
> >>
> >>None of  the other SPICE programs you can afford will use more
> >>than one CPU-core.
> >>
> >>Best regards,
> >>Helmut
> >>
> >
> >Great!
> >
> >I checked my LTspice version ..it's version 2.25d :( Ugh..
> >I'll get version 4.
> >
> >Thanks
> >
> >
> >D from BC
> >myrealaddress(at)comic(dot)com
> >British Columbia
> >Canada
> 
> I'm running LTspice4 now. Confirmed using help/about.
> However. in Windows task manager scad3.exe is running.. huh...
> 
> Anyways.. 
> My spice is not running faster and Windows Task Manager is only
> showing CPU usage at 50%. iow...1 virtual core saturated.
> 
> I did spot the max treads option under the LTspice control panel.
> It's set to 2.
> 
> I haven't noticed a change in speed. :(
> 
> 
> D from BC
> myrealaddress(at)comic(dot)com
> British Columbia
> Canada
> 
Welcome to the world of virtual cores.
What you REALLY have is the ability of the core to run different threads 
at once as long as they do not need the same resources.
So, if you have a bunch of threads waiting for the floating point unit 
and nothing waiting for the integer unit, you will have no performance 
gains.  Intel has loads of information on their website on this.  The 
advantage comes when running multiple apps, odds are you will be able to 
utilize more of the core's overhead that way.  
You want to get REAL gains you need REAL cores, although the i7 is 
suppose to do much better with the new Hyperthreading.  Vista thinks I 
have 8 cores to play with.

On Tue, 20 Jan 2009 13:28:23 -0800, D from BC
<m...@comic.com> wrote:

>On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
><h...@t-online.de> wrote:
>
[snip]
>>
>>You can get what you asked for if you use the latest LTspiceIV.
>>It will stress all your CPU-cores to its limits. Let's see when the first
>>people will claim LTspice has burned their Quadcore-CPUs because
>>of  running long lasting simulation runs. :-)
>>
>>None of  the other SPICE programs you can afford will use more
>>than one CPU-core.
>>
>>Best regards,
>>Helmut
>>
>
>I wonder if the other SPICE program writers are massively pissed about
>LTspice being free.

No.  Engineers don't choose simulators, jerks in management do...
that's why Cadence sales are so high, even though, IMNSHO, it's a
royal piece-a-crap, grossly user unfriendly and butt slow.

[snip]

                                        ...Jim Thompson
-- 
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 I love to cook with wine     Sometimes I even put it in the food

"D from BC" <m...@comic.com> schrieb im Newsbeitrag 
news:p...@4ax.com...
> On Tue, 20 Jan 2009 13:06:51 -0800, D from BC
> <m...@comic.com> wrote:
>
>>On Tue, 20 Jan 2009 21:13:44 +0100, "Helmut Sennewald"
>><h...@t-online.de> wrote:
>>
>>>"D from BC" <m...@comic.com> schrieb im Newsbeitrag
>>>news:d...@4ax.com...
>>>>I have an old single core puter using hyperthreading with XP.
>>>>
>>>> If I got this right..
>>>> XP thinks it's got 2 CPU's.
>>>> One thread will only use 50% of CPU mips.
>>>> So when I run spice, the CPU is only 1/2 working.
>>>> The other half is for whatever...email,browser,OS stuff etc.
>>>>
>>>> I want spice to at full speed.
>>>> Is there a way to set XP such that only my spice app gets nearly full
>>>> CPU attention?
>>>> When the spice app is not running, the computer goes back to 50 50
>>>> hyperthreading.
>>>>
>>>> Note: I do have the option in bios to disengage hyperthreading.
>>>> I might do that if hyperthreading is being a pita.
>>>>
>>>>
>>>> D from BC
>>>> myrealaddress(at)comic(dot)com
>>>> British Columbia
>>>> Canada
>>>
>>>
>>>Hello,
>>>
>>>You can get what you asked for if you use the latest LTspiceIV.
>>>It will stress all your CPU-cores to its limits. Let's see when the first
>>>people will claim LTspice has burned their Quadcore-CPUs because
>>>of  running long lasting simulation runs. :-)
>>>
>>>None of  the other SPICE programs you can afford will use more
>>>than one CPU-core.
>>>
>>>Best regards,
>>>Helmut
>>>
>>
>>Great!
>>
>>I checked my LTspice version ..it's version 2.25d :( Ugh..
>>I'll get version 4.
>>
>>Thanks
>>
>>
>>D from BC
>>myrealaddress(at)comic(dot)com
>>British Columbia
>>Canada
>
> I'm running LTspice4 now. Confirmed using help/about.
> However. in Windows task manager scad3.exe is running.. huh...
>
> Anyways..
> My spice is not running faster and Windows Task Manager is only
> showing CPU usage at 50%. iow...1 virtual core saturated.
>
> I did spot the max treads option under the LTspice control panel.
> It's set to 2.
>
> I haven't noticed a change in speed. :(
>
>
> D from BC
> myrealaddress(at)comic(dot)com
> British Columbia
> Canada

Hello,

I just tried a SMPS simulation.
LTspiceIV has a caused a CPU usage of 100% on my dual core CPU on Win-XP.
The gain regarding simulation speed depends on the circuit size.
Small circuits will not gain much in speed. Large circuits will
run up to 3 times faster on a quad core CPU compared to a
single core CPU with the same clock frequency.

Best regards,
Helmut