Is this Intel i7 machine good for LTSpice?

On Sun, 02 Nov 2014 09:53:42 -0800, Joerg <news@analogconsultants.com>
wrote:

>Any guess how long MS will support Win-7?

Jan 13, 2015
<http://windows.microsoft.com/en-us/windows/lifecycle>
Extended support means that MS will gladly continue supporting Windoze
7 if you throw money at them.  MS is following the Apple policy of
killing everything that's more than 5 years old (except in California,
which is 7 years):
<http://support.apple.com/en-us/ht1752>

>When it comes to PCs I am lazy :-)

That's why I'm still in business to seperate such customers from their
money.  Lazy is good for supporting my decadent and lavish lifestyle.

>I just want to plug it in and go. Re-installing all my stuff takes
>enough time already.

It's fairly easy to migrate programs and data from most anything to
Windoze 7.
<http://www.dummies.com/how-to/content/how-to-use-easy-transfer-in-windows-7.html>
<http://windows.microsoft.com/en-us/windows7/products/features/windows-easy-transfer>
However, Easy Transfer disappeared in Windoze 8.1, so you're either on
your own or purchase a 3rd part program to do the dirty work.

>> Before buying anything, I suggest you try LTspice on the new machine.
>> This is VERY easy with LTspice which doesn't use the registry or
>> require admin rights.  Just copy the files to a flash drive and it
>> should work.  
>
>I am quite sure Costco will not let me do this :-)

It's easier to obtain forgiveness than permission.

Are you really going to spend $1,300+ for a new machine without even a
test drive?  Costco has a very good return policy, but you still have
to haul it home, get it running, update, tweak, tune, and then try. If
unacceptable, you get to try and fit everything back into the original
box (which never seems to fit).  This is not being lazy.





-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

On a sunny day (Sun, 02 Nov 2014 10:21:33 -0800) it happened John Larkin
<jlarkin@highlandtechnology.com> wrote in
<6erc5ahtpf0buuavb0fpbidbbeqi60v9r1@4ax.com>:

>I'll have to tweak resistors and capacitors, and the cap values are
>too big for variable capacitors. And, as noted, it would be hard to
>instrument.
>
>Here's the current output when the load voltage steps from about 0.5
>to 3 volts.
>
>>https://dl.dropboxusercontent.com/u/53724080/Circuits/Current_Sources/Hysterical_A1.jpg
>
>I want it as flat as possible.

It looks a bit under-compensated, as if it takes time for it to respond to a load change.
It can probably never be faster than the /\/\/ cycles, but should be possible bette rthan this.
Diff part..

>The fast ripple is the basic 1.5 MHz switcher frequency. The various
>whoopie-doos are from loop dynamics and the chain of progressively
>smaller, bias-tee-like damped inductors between the switcher and the
>load. The constant-current hysterical switcher is, natively, about 4
>or so orders of magnitude too slow for my application.
>
>Everything interacts with everything else; it's like tuning a big LC
>filter by hand, never a fun thing to do. Spice helps me acquire at
>least some instincts for tuning. Maybe I can fix the cap values and
>tune only resistors on the breadboard.
>
>Rob, one of my guys, has a fierce Linux computer just for sims and
>FPGA compiles, and he knows how to do automatic iterative parts value
>tweaking in a loop around Spice. Maybe he can set up the problem and
>run it for a couple of days or weeks.
>
>I could probably step each of the six most important values, maybe 4
>steps each, and pick the best waveform. That would be 4096 sims, about
>60 hours of computing on my PC.


I have never been a PID guy, really, I have a simlilar problem here with frequency stabilization.
been testing large part of the day, reading many papers, got things working,
got severely pissed with Analog Devices (they provide PLL calculation soft that refuses to run under Linux wine,
even seems encryped, takes hour to un-encrypt, then cannot find DLLs), OK,
then I decided to do it in all software and not buy their chip.
I think the software solution can be better than their chip, anyways, experiment is fun :-)
I have coded it, but really need to watch some movie to prevent electronics overdose.

On Sun, 02 Nov 2014 09:28:33 -0800, Joerg <news@analogconsultants.com>
wrote:

[snip]
>
>I use the .STEP command a lot, sometimes nested. Then I get multiple
>sets of curve sets. But often I have to start it at night and see the
>results the next morning. The nice thing in winter is that this
>pre-heats the office.
>
>
[snip]

Here's how I handle a system that has multiple, interrelated
adjustments.  I just .STEP CASE from 1 to 4...

.PARAM         VDD={ROW1+ROW2+ROW3+ROW4}
+ B1V8={IF(CASE==3,1,0)+IF(CASE==4,1,0)}
+ S3V3={IF(CASE==2,1,0)+IF(CASE==4,1,0)}
+ CASE=4
+ PVDD=1  ; 0=TYP, -1=MIN, 1=MAX
ROW1={IF((CASE==1)&(PVDD==0),3.3,0)+IF((CASE==1)&(PVDD==-1),2.5,0)+IF((CASE==1)&(PVDD==1),3.6,0)}
ROW2={IF((CASE==2)&(PVDD==0),2.5,0)+IF((CASE==2)&(PVDD==-1),2.35,0)+IF((CASE==2)&(PVDD==1),2.75,0)}
ROW3={IF((CASE==3)&(PVDD==0),3.0,0)+IF((CASE==3)&(PVDD==-1),2.7,0)+IF((CASE==3)&(PVDD==1),3.3,0)}
ROW4={IF((CASE==4)&(PVDD==0),3.3,0)+IF((CASE==4)&(PVDD==-1),3.0,0)+IF((CASE==4)&(PVDD==1),3.6,0)}
		
                                        ...Jim Thompson
-- 
| James E.Thompson                                 |    mens     |
| Analog Innovations                               |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             |
| 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.

On 11/2/2014 10:25 AM, Joerg 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

Hard to say.  The devil is in the details.  I have an i7 and I'm not 
convinced it is much better if any than other CPUs for most tasks.  One 
problem with the quad core is that that each core still runs at the same 
speed as a dual core or even slower due to the contention for memory 
bandwidth.  That is why I got a laptop with separate graphic memory. 
But overall I don't see big speed improvements.  I'd be willing to bet 
you won't see a huge difference between this machine and one costing a 
few hundred dollars less.  BTW, do you really need a new monitor?  I 
expect you can save a couple hundred more by getting a unit without 
monitor.


> 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.

I use LibreOffice which is the same package from the developers who 
jumped ship at Oracle to continue development of OpenOffice the way they 
think is best.  I don't see compatibility issues and 90% of what I use 
office for is the spreadsheet.


> 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.

Get something tailor made.  You can get both the best machine and the 
cheapest that way.  After all, they are all made from the same parts. 
It is just a question of who puts them together.

-- 

Rick

On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <news@analogconsultants.com>
wrote:

>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

How well does LTSpice spread simulation cycles between multiple
processors and multiple cores (Hyperthreading etc.) ?

On 11/2/2014 12:53 PM, Joerg wrote:
> Jeff Liebermann wrote:
>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <news@analogconsultants.com>
>> wrote:
>>
>> LTspice benchmark on various machines:
>> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>>
>>> 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.
>>
>> Windoze 8.1 can be made semi-tolerable by putting the start menu back
>> in and making it look like Windoze 7.
>> <http://www.classicshell.net>
>> I've been installing it on all my customers Windoze 8.1 machines and
>> have had no complaints or problems.  If you like wiggly icons on the
>> Windoze 8.1 start screen, you can do <Shift><Start>.
>>
>
> Too much risk. I've heard that running legacy software is tough in Win-8
> but Win-7 can mostly do it. Not as good as XP.

What legacy software?  I have Windows 8 and I'm not having problems 
running anything I ran on my old Vista laptop.


> When it comes to PCs I am lazy :-)
>
> I just want to plug it in and go. Re-installing all my stuff takes
> enough time already.

I hear you.  The big problem I had with setting up my Win 8 laptop was 
that a lot of the freeware has become burdened with ads, toolbars and 
other malware to the point I'm not willing to use it.


>> Before buying anything, I suggest you try LTspice on the new machine.
>> This is VERY easy with LTspice which doesn't use the registry or
>> require admin rights.  Just copy the files to a flash drive and it
>> should work.
>
> I am quite sure Costco will not let me do this :-)

You can try finding the computer salesperson in the store.  They are 
limited by store policy of course, but I have met a few who were very 
willing to help as best they could.


>> One catch.  LTspice saves its preferences to:
>>    C:\windows\scad3.ini
>> which has to be writeable.  The fix is to use the
>>    -ini <path>
>> command line switch, which will:
>>    Specify an .ini file to use other than %WINDIR%\scad3.ini
>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>

I need to note this somewhere.  Writing to the Windows directory is a 
*very* bad idea.  I can't tell you how many developers do all sorts of 
things they aren't supposed to under windows.  That is the actual cause 
of many problems people have running older software under Windows.  They 
don't listen to the people providing them with the OS!

-- 

Rick

"Joerg"  wrote in message news:cbn7m2Fla99U1@mid.individual.net...

Joerg wrote:
> Carl Ijames wrote:
>> Don't know about computation speed, but this link says the video card 
>> will
>> drive 3 monitors:
>> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/specifications.
>> Looking at Dell's site I don't see any mention of expansion slots, and
>> looking at the one picture with the cover off I really can't see any 
>> sockets
>> beyond the video card, so if any further expansion is important you need 
>> to
>> ask Dell for clarification.
>>
>
> Looks like you are right:
>
> http://www.dell.com/ed/business/p/xps-8700/pd
> http://core0.staticworld.net/images/article/2013/07/1253541_sr-1160-100047019-orig.jpg
> http://www.pcworld.com/article/2047487/dell-xps-8700-special-editions-review-a-little-less-performance-for-a-lot-less-cash.html
>
> Quote "There's only one PCIe x16 slot, which means you won't be able to
> add a second video card to take advantage of Nvidia's SLI technology".
>
> No slots. There's one more card in the bottom, not sure what that is.
> But if the video can drive three monitors it should be fine, I never
> added any cards to my current PC either.
>

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

-- 
Regards, Joerg

http://www.analogconsultants.com/
==============================================================================

That's the gotcha, you need a different cable to each monitor.  I'm no 
expert, but I have an ATI Radeon HD5670 that supports 3 monitors and has the 
same three connectors so I have my main monitor connected with the DVI-D 
cable and my TV set connected with HDMI so I can watch video files on the TV 
(I have a Hauppage tuner card and use my pc as dvr).  I don't use the third 
output.  The installation guide shows pictures of adaptors from hdmi and 
svga to dvd-d so if you used those you could use all dvd-I monitors, but 
I've never looked for them so can't give any advice there.  There might be a 
lower max resolution on the svga output.  The video driver lets me choose 
which monitor is which and how to arrange them., so that is painless.

-----
Regards,
Carl Ijames

Den s=F8ndag den 2. november 2014 18.24.23 UTC+1 skrev Joerg:
> Joerg wrote:
> > Carl Ijames wrote:
> >> Don't know about computation speed, but this link says the video card =
will=20
> >> drive 3 monitors:=20
> >> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/specificat=
ions.=20
> >> Looking at Dell's site I don't see any mention of expansion slots, and=
=20
> >> looking at the one picture with the cover off I really can't see any s=
ockets=20
> >> beyond the video card, so if any further expansion is important you ne=
ed to=20
> >> ask Dell for clarification.
> >>
> >=20
> > Looks like you are right:
> >=20
> > http://www.dell.com/ed/business/p/xps-8700/pd
> > http://core0.staticworld.net/images/article/2013/07/1253541_sr-1160-100=
047019-orig.jpg
> > http://www.pcworld.com/article/2047487/dell-xps-8700-special-editions-r=
eview-a-little-less-performance-for-a-lot-less-cash.html
> >=20
> > Quote "There's only one PCIe x16 slot, which means you won't be able to
> > add a second video card to take advantage of Nvidia's SLI technology".
> >=20
> > No slots. There's one more card in the bottom, not sure what that is.
> > But if the video can drive three monitors it should be fine, I never
> > added any cards to my current PC either.
> >=20
>=20
> Only question is, how can one connect two regular OPC monitors to this?
>=20
> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-image=
s
>=20

I'd expect that you can connect a monitor to each of the three outputs,=20
VGA,DVI,HDMI. I have an old geforce and that's how that works

VGA is not much use, but unless you want to watch something from Hollywood=
=20
DVI and HDMI is the same thing


-Lasse

On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <news@analogconsultants.com>
Gave us:

>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

  That actually looks like a really nice deal.  You can't go wrong.
Mine cost me $2500 and took over a year to build as budgets tightened.

 I'll bet my 3930K beats it though.

  The newer fabs have higher GHz rates, but are not as fast as their
first series were, which the smaller fabs replaced..

  I have 6x2 cores, and I don't even know if they do that any more
except on Xeons.

  I scream past all the benchmarks.  Two more cores really makes a
difference.  I beat machines pegging faster raw "speeds" all the time.
Mainly because they only have 4x2 cores.

  Not cheap.  The i7-3930K was $695, and the X79 Mobo under it was $400.
The 32GB RAM was not cheap either for 2133MHz, And that was before the
2400MHz stuff appeared.  I can still upgrade the GPU and the RAM and get
even faster.

  Since I cannot afford to put $1000 into a Titan video card, I miss on
a few benchmarks with my $250 GTX650.

On Sun, 02 Nov 2014 09:46:45 -0800, Jeff Liebermann <jeffl@cruzio.com>
Gave us:

>
>The Dell XPS 8700 seems like a nice machine.  However, if you want
>performance, I suggest you look at an SSD drive for the OS.

  Even better than those are the mSATA drives and now, the best...  the
M.2 drives.

  Not much bigger than a couple of air mail stamps (I date myself).

  Way faster than the 2.5" form factor SSD "laptop drive" replacement
family.

  Even an mSATA drive in a USB3 enclosure/interface plugged into a USB 2
port boots up faster.  As you can see, I am impressed.
You would be as well.

  I would look into M.2 drives as they are the hot, emerging storage
tech right now, and they DO make a difference.

  Even with your SSD variety, machines scream in benchmarks.

  And this is OLD stuff.  Things are way faster now than even that.

http://www.youtube.com/watch?v=eULFf6F5Ri8