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 HobbsThere's a setting for one or two threads. Is that all? -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Is this Intel i7 machine good for LTSpice?
Started by ●November 2, 2014
Reply by ●November 2, 20142014-11-02
Reply by ●November 2, 20142014-11-02
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>. The damage control version of Windoze 10, that is possibly due some time in the distant future, restores the start menu: <http://windows.microsoft.com/en-us/windows/preview> but otherwise currently looks like Windoze 8.1. Incidentally, Halloween was the last day that Microsoft will ship Windoze 7 licenses to OEM's. 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. <http://www.newegg.com/Internal-SSDs/SubCategory/ID-636> I've had good luck with Samsung 840 EVO series drives (mostly 250GB). The ritual is simple. I use Acronis True Image 2014 (not 2015) to clone the hard disk to the SSD. I then replace the hard disk with the SSD and test everything. When done, I wipe the hard disk, and install it as a 2nd hard disk. If I need to return everything to stock, I have the Acronis True Image 2014 backup image with which to recover the initial installation. Elapsed time on a typical fast system is about 1 hr. 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. 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> -- 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
Reply by ●November 2, 20142014-11-02
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.> The damage control version of Windoze 10, that is possibly due some > time in the distant future, restores the start menu: > <http://windows.microsoft.com/en-us/windows/preview> > but otherwise currently looks like Windoze 8.1. > > Incidentally, Halloween was the last day that Microsoft will ship > Windoze 7 licenses to OEM's.Any guess how long MS will support Win-7?> 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. > <http://www.newegg.com/Internal-SSDs/SubCategory/ID-636> > I've had good luck with Samsung 840 EVO series drives (mostly 250GB). > The ritual is simple. I use Acronis True Image 2014 (not 2015) to > clone the hard disk to the SSD. I then replace the hard disk with the > SSD and test everything. When done, I wipe the hard disk, and install > it as a 2nd hard disk. If I need to return everything to stock, I > have the Acronis True Image 2014 backup image with which to recover > the initial installation. Elapsed time on a typical fast system is > about 1 hr. >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.> 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 :-)> > 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> > > > > > > >-- Regards, Joerg http://www.analogconsultants.com/
Reply by ●November 2, 20142014-11-02
I have a two year old laptop. I was tired with the slow startup of programs, so I replaced the hard disk with a SSD. Amazing difference in speed. As far as I can see also for the simulations although I did not do a benchmark test. The Kingston SSD came with a USB connected enclosure to mount the old hard disk in, so the harrdisk was mirrored and no re install of programs was needed Cheers Klaus
Reply by ●November 2, 20142014-11-02
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. 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
Reply by ●November 2, 20142014-11-02
On 11/2/2014 12:31 PM, Joerg wrote:> Phil Hobbs 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. >> > > But they should work on their web site some more or get rid of scripting > or whatever. Other than a language selector it shows ... nothing. >Probably a NoScript issue, or something like that. Talk to Alexander at alvio.com a primo Supermicro reseller, and tell him "Hi" from me. 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
Reply by ●November 2, 20142014-11-02
On Sun, 02 Nov 2014 16:21:32 GMT, Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:>On a sunny day (Sun, 02 Nov 2014 08:00:36 -0800) it happened John Larkin ><jlarkin@highlandtechnology.com> wrote in ><0nkc5aljhec5r36ptkoaqbt0a48ud2j5vo@4ax.com>: > >>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. > >Maybe building the real thing with some pots?I am halfway through building a breadboard; I'll post pics. I'm after extreme broadband high impedance output, which is hard to measure on a breadboard; Spice lets me graph all sorts of currents and nodes, so it's the best platform for development.>But without some theory backing it up how would you know it always works?I'll have to simulate, and then test, the thing over a range of loads.>And with the theory you do not need the sliders.I don't have sufficient theoretical skills to tune this circuit. I'm not sure if anyone does.> >I do not see the need for insane speeds, I have used LTspice more than often >the last few days, running on an old Duron 950, fast enough. >maybe you guys are doing something wrong?At 30-50 seconds per run, iteration is slow. Worse, the time lag wrecks my ability to acquire intuition about what's going on.>:-) > >And it is always an approximation, build the real thing too, >needed tweaking with resistors in series, that is analog, >got some nice 25 turn Bourns trimpots from ebay.....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.jpgI want it as flat as possible. 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. -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●November 2, 20142014-11-02
On Sun, 02 Nov 2014 09:28:33 -0800, Joerg <news@analogconsultants.com> wrote:>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. >> > >That's exactly why I need all the speed I can get. > > >> 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. >> > >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. > > >> Mike should code LT Spice to execute on a high-end video card. >> > >There are so many variants of graphics cards that it would require tons >of work for Mike's team.Just pick one of the Nvidia number cruncher monsters. There are C compilers available. You can buy an Nvidia "video" board with no video out; it's just a 200 or something core compute engine. Maybe the SuperSpice guy is interested. There's money there. -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●November 2, 20142014-11-02
On Sun, 02 Nov 2014 07:25:49 -0800, the renowned 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.Looks pretty decent for the money, 32G is a sensible amount of RAM- the RAM speed might be a bit on the low side though. I only research this stuff when I'm shopping for a new box, but that stands out. You can get a 1T Samsung SSD for only about $450, which allows you to leave the mechanical one it comes with (worth < $100) pristine and to be returned with the computer if necessary (so no proprietary information can escape). Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by ●November 2, 20142014-11-02
"John Larkin" <jlarkin@highlandtechnology.com> wrote in message news:0nkc5aljhec5r36ptkoaqbt0a48ud2j5vo@4ax.com...> 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.You can do that in Multisim, but it's single thread only, no faster than any other simulator. Tim -- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com
