Is this Intel i7 machine good for LTSpice?

On 3 Nov 2014 06:20:45 GMT, Jasen Betts <jasen@xnet.co.nz> Gave us:

>On 2014-11-02, Joerg <news@analogconsultants.com> wrote:
>
>> Only question is, how can one connect two regular OPC monitors to this?
>>
>> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-images
>
>Assuming you consider VGA to be irregular use a HDMI to DVI cable for
>the other,

  Most video cards even come with an adapter these days.

Jeff Liebermann wrote:

> On Sun, 02 Nov 2014 21:08:42 -0800, miso <miso@sushi.com> wrote:
> 
>>The Samsung 840 series has a speed bug. The fix is in flux, so it is best
>>to do an internet search for this issue. Samsung released a windows
>>program to "fix" the problem.
>>
>>I unfortunately have the 840 in this PC but I run linux, so their fix
>>isn't so handy.
> 
> The Linux fix is on the Samsung web pile in the form of a bootable CD:
> 
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/support/downloads.html>
> Near bottom of page.  I've only done the Windoze version once.  When
> it works, it's quite simple.  However, if the "advanced mode" is
> required, it's an ordeal.  As always, make an image backup before
> doing anything this radical.
> 

Thanks. I downloaded the ISO and the instructions.

In the dark ages, you would get a file to put on a floppy to upgrade 
firmware. Then the manufactures decided that they would just distribute a 
windows program. Nice, but if you don't run windows, well not so nice.

My blueray has new firmware.
> http://www.lg.com/us/support-product/lg-WH14NS40
Only windows solutions. Now it isn't like I don't have a windows box handy, 
but this shouldn't be necessary. If windows wasn't so damn expensive, I 
could dual boot everything, but I don't like paying the Microsoft tax. I 
have three copies of win7 pro. Enough is enough.\

I'm going to research the firmware upgrade path prior to buying any more 
peripherals. 

John Larkin wrote:

>>Spice is not a design tool. It is a verification tool.
>>
>>
> 
> Of course it's a design tool. Why spend a half hour cranking out a
> voltage divider network with a calculator, when you can Spice and
> fiddle a solution in a few minutes?
> 
> Is a calculator a design tool? Is an equation a design tool?
> 
> 

A voltage divider. We're talking Ohm's law here. You would really resort to 
Spice to design something that can be done simply with middle school 
algebra? 

Have I used Spice to analyze a resistor divider? Actually yes, but in finite 
element analysis to simulate a laser trim procedure. The basic networks are 
designed by hand. 

On 11/02/2014 01:17 PM, Phil Hobbs wrote:
> On 11/2/2014 12:45 PM, John Larkin wrote:
>> On Sun, 02 Nov 2014 11:06:30 -0500, Phil Hobbs
>> <hobbs@electrooptical.net> wrote:
>>
>>> On 11/2/2014 11:00 AM, John Larkin wrote:
>>>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <news@analogconsultants.com>
>>>> wrote:
>>>>
>>>>> Folks,
>>>>>
>>>>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt
>>>>> stated
>>>>> that the Intel i7 is a really good processor for LTSPice. According to
>>>>> this it looks like the 4790 is the fastest of the bunch:
>>>>>
>>>>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>>>>
>>>>>
>>>>> So, what do thee say, is the computer in the Costco link below a good
>>>>> deal for LTSpice purposes?
>>>>>
>>>>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>>>>
>>>>>
>>>>> It's also available without MS-Office Home & Student 2013 for $100
>>>>> less
>>>>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>>>>> that sounds like an ok deal. My hope is that it can drive two 27"
>>>>> monitors but I guess I can always add in another graphics card if not.
>>>>>
>>>>> Reason I am looking at these is that I absolutely positively do not
>>>>> want
>>>>> any computer with Windows 8 in here and unfortunately that's what many
>>>>> others come with.
>>>>
>>>> I have spent too many hours this weekend tweaking the transient
>>>> response of a semi-hysteretic (we call it "hysterical") switchmode
>>>> constant-current source. There are about 8 interacting knobs to turn.
>>>> At 30 seconds per run, understanding the interactions is impossible.
>>>>
>>>> I want sliders on each of the part values, and I want to see the
>>>> waveforms change as I move the sliders, like they were trimpots on a
>>>> breadboard and I was looking at a scope. I need maybe 500 times the
>>>> compute power that I have now.
>>>>
>>>> Mike should code LT Spice to execute on a high-end video card.
>>>>
>>>>
>>>
>>> You can go quite a bit faster with a nice multicore machine--LTspice
>>> lets you choose how many threads to run.  My desktop machine (about 3
>>> years old now) runs about 150 Gflops peak.  Supermicro is an excellent
>>> vendor.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> There's a setting for one or two threads. Is that all?
>>
>>
> That's because you only have two cores.  Mine goes up to 15.

16 actually.  Here's a picture:
http://electrooptical.net/pictures/LTspice16threads.png

Cheers

Phil Hobbs
>
> Cheers
>
> Phil Hobbs
>


-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

On 03/11/2014 04:04, miso wrote:

> I'm on a quad core Xeon, which means I can have 8 threads. Also a Supermicro
> motherboard with 32G of error correcting RAM. Basically a low end
> workstation.
>
> LT Spice has been multithreaded for about 5 years now, but the nature of
> spice simulation won't lead to a linear speed up with the number of cores.
> In fact, your setting of three makes sense based on system monitor analysis.

The more interesting question is whether the i7 with 4 cores and 
hyperthreading to run 8 threads actually provides any better performance 
with LTSpice than the corresponding i5 with 4 real cores and no 
hyperthreading. Sometimes 5 or 6 threads is optimum but quite often in 
search problems it consumes power without speeding it up!

In some chess problems the i5 can be faster and certainly cheaper!

Be interested to know if it holds with LTSpice too.

-- 
Regards,
Martin Brown

On Mon, 03 Nov 2014 01:43:29 -0800, miso <miso@sushi.com> wrote:

>John Larkin wrote:
>
>>>Spice is not a design tool. It is a verification tool.
>>>
>>>
>> 
>> Of course it's a design tool. Why spend a half hour cranking out a
>> voltage divider network with a calculator, when you can Spice and
>> fiddle a solution in a few minutes?
>> 
>> Is a calculator a design tool? Is an equation a design tool?
>> 
>> 
>
>A voltage divider. We're talking Ohm's law here. You would really resort to 
>Spice to design something that can be done simply with middle school 
>algebra? 

If it saves me time, absolutely. 

>
>Have I used Spice to analyze a resistor divider? Actually yes, but in finite 
>element analysis to simulate a laser trim procedure. The basic networks are 
>designed by hand. 

Do that if you enjoy it. I'd rather get scut work like that over as
soon as possible, which is often Spice + twiddle.

Here's a divide-and-offset network designed by fiddling. The object
was to map +-10.5 volts or so into the unipolar ADC range with
available parts, already on the BOM. The final close-enough in:out
transfer function was determined by Spice, then plugged into the ARM
code... the opposite of the classic design direction. A bonus is that
the .asc file is part of the permanent design record, and easily
revisited if ever necessary.

This took minutes.

Version 4
SHEET 1 880 680
WIRE 224 -16 112 -16
WIRE 112 16 112 -16
WIRE 224 64 224 -16
WIRE 112 128 112 96
WIRE -192 192 -256 192
WIRE -48 192 -112 192
WIRE 0 192 -48 192
WIRE 48 192 0 192
WIRE 224 192 224 144
WIRE 224 192 128 192
WIRE 400 192 224 192
WIRE 448 192 400 192
WIRE -256 240 -256 192
WIRE 224 240 224 192
WIRE -48 256 -48 192
WIRE -256 368 -256 320
WIRE -48 368 -48 336
WIRE 224 368 224 320
FLAG -256 368 0
FLAG 224 368 0
FLAG 112 128 0
FLAG -48 368 0
FLAG 400 192 ADC
FLAG 0 192 IN
SYMBOL res 208 48 R0
WINDOW 0 60 44 Left 2
WINDOW 3 60 79 Left 2
SYMATTR InstName R1
SYMATTR Value 1K
SYMBOL res 208 224 R0
WINDOW 0 50 37 Left 2
WINDOW 3 51 71 Left 2
SYMATTR InstName R2
SYMATTR Value 1K
SYMBOL res 144 176 R90
WINDOW 0 67 56 VBottom 2
WINDOW 3 73 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 2K
SYMBOL voltage -256 224 R0
WINDOW 0 55 68 Left 2
WINDOW 3 39 109 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 10.15
SYMBOL voltage 112 0 R0
WINDOW 0 -80 43 Left 2
WINDOW 3 -73 81 Left 2
SYMATTR InstName V2
SYMATTR Value 3
SYMBOL res -64 240 R0
WINDOW 0 51 44 Left 2
WINDOW 3 52 75 Left 2
SYMATTR InstName R5
SYMATTR Value 50
SYMBOL res -96 176 R90
WINDOW 0 -51 49 VBottom 2
WINDOW 3 -37 49 VTop 2
SYMATTR InstName R6
SYMATTR Value 50
TEXT 280 -8 Left 2 ;PIEZO DIVIDER FOR Z354 TEST BOARD
TEXT 376 40 Left 2 ;JL  JULY 30  2014
TEXT 352 240 Left 2 ;ARM ADC RANGE IS 0 TO +3
TEXT 488 136 Left 2 !;tran 3
TEXT 344 280 Left 2 ;PIEZO DAC RANGE +-10.15V
TEXT 504 104 Left 2 !.op

-- 

John Larkin         Highland Technology, Inc

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

On Mon, 03 Nov 2014 13:14:47 +0000, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> Gave us:

>In some chess problems the i5 can be faster and certainly cheaper!

  Bullshit.

On 03/11/2014 16:26, DecadentLinuxUserNumeroUno wrote:
> On Mon, 03 Nov 2014 13:14:47 +0000, Martin Brown
> <|||newspam|||@nezumi.demon.co.uk> Gave us:
>
>> In some chess problems the i5 can be faster and certainly cheaper!
>
>    Bullshit.

You demonstrate clearly that you are an inarticulate moron.
Why am I not surprised?

It is easy enough to do the tests and see for yourself. Hyperthreading 
can get in the way of fast multithreading in some larger problems.

-- 
Regards,
Martin Brown

On Mon, 03 Nov 2014 16:48:29 +0000, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> Gave us:

>On 03/11/2014 16:26, DecadentLinuxUserNumeroUno wrote:
>> On Mon, 03 Nov 2014 13:14:47 +0000, Martin Brown
>> <|||newspam|||@nezumi.demon.co.uk> Gave us:
>>
>>> In some chess problems the i5 can be faster and certainly cheaper!
>>
>>    Bullshit.
>
>You demonstrate clearly that you are an inarticulate moron.
>Why am I not surprised?
>
>It is easy enough to do the tests and see for yourself. Hyperthreading 
>can get in the way of fast multithreading in some larger problems.

  Again..  you spout crap, but have no clue about actual operation or
function.

  I can turn OFF HT in my Motherboard BIOS setup.

  I will bet you that your chess app runs the same in both settings, if
the code never uses it.

   So, no...  it typically NEVER "gets in the way", and YOU need to cite
a condition where it does, not merely spout off horseshit as if you are
a fucking professor.

  Your brain benchmark takes a big hit when you pull this stupid
guesswork bullshit.

"John Larkin"  wrote in message 
news:0nkc5aljhec5r36ptkoaqbt0a48ud2j5vo@4ax.com...


>I have spent too many hours this weekend tweaking the transient
>response of a semi-hysteretic (we call it "hysterical") switchmode
>constant-current source. There are about 8 interacting knobs to turn.
>At 30 seconds per run, understanding the interactions is impossible.

Only 30 seconds, Luxury. A large bulk of my sims at work are in the 15 mins 
to 1 hour range, some take overnight.

>I want sliders on each of the part values, and I want to see the
>waveforms change as I move the sliders, like they were trimpots on a
>breadboard and I was looking at a scope. I need maybe 500 times the
>>compute power that I have now.

It doesn't look like you need core compute power to me, you want a spice 
with real time control of components for this particular method of, er.. 
ahmmm.. "pissing" about design approach.

You can actually do this in SS. If real time mode is enabled, with marching 
waveforms also enabled, changing component like resistors and caps will 
update the simulation  matrix immediately and the marching waveform will 
reflect this. There are other spice programs out there that are better 
designed for real time technician twiddling though.

The er...hmmm.. more professional way is to set up multi way sweeps of all 
the pots you want to twiddle, and examine the resulting set of graphs. You 
can gain intuition by doing this, even after the fact. That's what those 
that generate millions of asic chips do anyway.

:-)

Kevin Aylward
www.kevinaylward.co.uk
www.anasoft.co.uk - SuperSpice