Keyboard Shortcuts
Likes
- LTspice
- Messages
Search
|
Re: LTspice XVII Co-exist with LTspice IV?
开云体育Hi Jim I m running both on WINE. So far so good. Al D.
On 08/15/2016 09:29 AM, Jim Thompson
ltlist@... [LTspice] wrote:
Can LTspice XVII Co-exist with LTspice IV on the same machine without -- AC2CL I do not think there is any thrill that can go through the human heart like that felt by the inventor as he sees some creation of the brain unfolding to success... Such emotions make a man forget food, sleep, friends, love, everything. - Nikola Tesla |
|
Re: Benchmarking the new LTspice
Greetings.. Here is some food for thought... Let us assume you have a computer ?which can support 4 threads... Assuming ? that the OS is smart in optimizing the workload , you ?should gt a maximum iimprovment of 3.5 to ?4 over ?a single thread...(Amdhal's law will kcik in somewhere) Take a large schematic with a long transient run... Repeat it 4 times on the main schematic page .. Make sure no nodes are named the same excepting ?input and 0.. We know that such a circuit matrix is inherently separable and solvable as 4 independent smaller matrices. Under this condition, allowing for overhead and Amdhal, you should see an improvement of?3-4 ?on the same machine over ?when you operate it with single thread.... Make sure you just simulate and don't plot anything.. Make the sim time very long to minimize overhead issues. On 4 threads, I have never been able to get this number over 2.7...... Cheers AG |
|
Re: Benchmarking the new LTspice
Hi If you want the fastest windows PC, look at "gaming" class computers. They have fast CPU (i7, 4Ghz or better), fast memory, SSD, Hi perf GPU and minimal I/O expansion.?The only thing you really don't need is the superfast GPU, unless your planning to use 3D graphics. |
|
Re: LTspice XVII Co-exist with LTspice IV?
Hi I'm running both versions also (WIn 10). If you Rht-click on a schematic .asc file, choose "Open With", then choose "Choose another app, The previous version will be listed in the "other options" section. The name is the same for both apps, but if you choose the one in "other options", it will launch the previously installed version |
|
Re: Benchmarking the new LTspice
John Woodgate
开云体育I suspect that Win 7 is recommended because most CAD programs have not yet been optimized for Win 10. ? With best wishes DESIGN IT IN! OOO – Own Opinions Only J M Woodgate and Associates Rayleigh England ? Sylvae in aeternum manent. ? From: LTspice@... [mailto:LTspice@...]
Sent: Monday, August 15, 2016 11:44 PM To: LTspice@... Subject: [LTspice] Benchmarking the new LTspice ? ? LTspice Yahoo Group readers, ? |
|
Re: Benchmarking the new LTspice
Allan,
toggle quoted message
Show quoted text
My home laptop is an older Lenovo quad core i7 and I also have an ancient dual core Pentium desktop machine that can't support Windows 7.? When I get home (after work and after my tennis match), I will run the benchmark on both and report back. I am looking to buy a Core i7 Extreme 6/12 or 8/16 that runs at 4.2 GHz or so with lots of RAM, a solid-state drive and super quiet cooling.? I am hoping it will be more than twice as fast as my office computer. ---In LTspice@..., <allanvv@...> wrote : I don't think you really need to go for a workstation PC. You wouldn't need an overpriced workstation GPU for basic CAD like for running SPICE or PCB design. My recommendation is to buy a good desktop CPU with 6-8 cores, buy a gigantic $50 CPU fan (Noctua), and overclock your CPU. While some simulations can make good use of 4+ cores, single-threaded perf is still really important for a lot of applications and you'll get a lot more performance than any stock computer. With a good heatsink+fan, you can get great single-core GHz above the Turbo Boost frequency, and also good 8-core performance at the TB frequency without even coming close to thermal limits. If I weren't traveling at the moment, I'd give you the performance of your benchmark at 6x4.4 GHz on a similar CPU generation. Allan
|
|
Re: Benchmarking the new LTspice
ehydra
It doesn't make sense to benchmark an 'unrealistic' circuit model. I would say it is badly written - or one can say lightyears ahead the current capability of LTspice in the senses of acceptable run-time.
toggle quoted message
Show quoted text
Say, a new user of LTspice chooses this example jig as a first trial to see if LTspice is fun. He will throw it away! And maybe the IC product too. For experts (freaks?) it might be interesting to see such benchmark results fiddling with Reltol et al.. I would prefer a more common example. No, I don't have one for the public AND interesting to many people. - Henry analogspiceman@... [LTspice] schrieb: LTspice Yahoo Group readers, It would be fun to see what run times other group members report for |
|
Re: Benchmarking the new LTspice
Allan Wang
I don't think you really need to go for a workstation PC. You wouldn't need an overpriced workstation GPU for basic CAD like for running SPICE or PCB design. My recommendation is to buy a good desktop CPU with 6-8 cores, buy a gigantic $50 CPU fan (Noctua), and overclock your CPU. While some simulations can make good use of 4+ cores, single-threaded perf is still really important for a lot of applications and you'll get a lot more performance than any stock computer. With a good heatsink+fan, you can get great single-core GHz above the Turbo Boost frequency, and also good 8-core performance at the TB frequency without even coming close to thermal limits. If I weren't traveling at the moment, I'd give you the performance of your benchmark at 6x4.4 GHz on a similar CPU generation. Allan On Mon, Aug 15, 2016 at 6:44 PM, analogspiceman@... [LTspice] <LTspice@...> wrote:
|
|
Benchmarking the new LTspice
LTspice Yahoo Group readers,
I am shopping for a new home computer optimized to run LTspice and have been corresponding with Orbital Computers. ? Danny Payne, the owner there was willing to benchmark LTspice for me.? He downloaded the new version (LTspice XVII) and tried running some of the test jigs.? He chose the 3752-1 test jig, which was a very good choice for someone not familiar with LTspice because he chose a file that maxes out all eight of my work computer's threads. However, it turns out that either the 3752-1 model or its test jig is not well written because it throws lots of Def Cons with the default simulation settings.? It runs much happier and faster with the Alternate Solver selected, Reltol relaxed to = 0.01 and Trtol set to 7 (click the Hammer icon to access the Control Panel and then click the Hammer tab to access the SPICE settings). On my (4 cores / 8 thread) Xeon E3-1240 v3 @ 3.40GHz with 8GB ram (NVIDIA Quadro K600) at work, the SPICE Error Log reports a run time of around 126 seconds (once the Alternate Solver has been selected and Reltol has been set to 0.01 and Trtol set to 7).? NOTE: Do not plot any traces when running this benchmark.? With the same simulation settings, the old LTspice IV runs this test jig in 137 seconds, which is about 8 percent slower. I am going to send Danny Payne this message and have him run the benchmark with the same settings on an LTspice optimized computer platform and report his results (as well as the system configuration details).? It is interesting that he recommends Windows 7 for all CAD programs. It would be fun to see what run times other group members report for this benchmark. |
|
Re: LTspice XVII Co-exist with LTspice IV?
John Woodgate
开云体育That 'w/' is a bit of a nonsense, too. 'With' or 'and' or even '&'.? But the whole reference to 'schematic capture' is surely a legacy from the days when that was a rarity. ? With best wishes DESIGN IT IN! OOO – Own Opinions Only J M Woodgate and Associates Rayleigh England ? Sylvae in aeternum manent. ? From: LTspice@... [mailto:LTspice@...]
Sent: Monday, August 15, 2016 9:45 PM To: LTspice@... Subject: [LTspice] Re: LTspice XVII Co-exist with LTspice IV? ? ? Hello Andy Whichever program you installed last, would be the one that automatically opens when you double-click on a schematic file. " ?Not ""SPICE Simulator w/ Schematic Capture" for both versions. |
|
Re: LTspice XVII Co-exist with LTspice IV?
Hello Andy
You wrote : " Whichever program you installed
last, would be the one that automatically opens when you double-click on a
schematic file. " That's the problem? : the same name for all LTspice versions. It would be very easy to change "SPICE Simulator w/ Schematic Capture " by "Spice simulator LT IV" for LTsice IV and? "Spice simulator LT XVII" for LTspice XVII ?Not ""SPICE Simulator w/ Schematic Capture" for both versions. Regards PhB |
|
Re: LTspice XVII Co-exist with LTspice IV?
开云体育Perhaps its time to submit a support call? ? Dave ? From: LTspice@... [mailto:LTspice@...]
Sent: 15 August 2016 19:04 To: [LTspice] group Subject: Re: [LTspice] Re: LTspice XVII Co-exist with LTspice IV? ? ? ?"In many circumstances you can right click and choose from a range of applications.." ? Good point. ? However, when I do that, both programs are named "SPICE Simulator w/ Schematic Capture" so I can't tell which is which. ?:-( ? Andy ? ? |
|
Re: I'm ready to give up LTC all toghether.
John Woodgate
开云体育Yes, you did what I advised and found the definitive answer. ? With best wishes DESIGN IT IN! OOO – Own Opinions Only J M Woodgate and Associates Rayleigh England ? Sylvae in aeternum manent. ? From: LTspice@... [mailto:LTspice@...]
Sent: Monday, August 15, 2016 7:43 PM To: [LTspice] group Subject: Re: [LTspice] Re: I'm ready to give up LTC all toghether. ? ? John wrote: ? ? ?"The formal definitions of rise time and fall time relate to 10 % and 90 % of the amplitude, because it's not possible to say precisely when the pulse is no longer 0 % and when it first reaches 100 %." ? That is correct for the method to use to measure rise time and fall time in the lab, where real signals are not straight with sharp corners. ? But for generating step waveforms in SPICE, the prescribed rise and fall times refer to the 0% and 100% points of the waveform edges.? This is the convention that UC/Berkeley adopted when they created SPICE some 40 years ago, and LTspice conforms to that convention. ? It definitely applies to the PULSE voltage and current source waveforms, and it apparently applies here (to the [Digital] library of A-devices) too.? I just tried it with a NAND gate, and that is what I saw. ? I did see some curvature in the output waveform, near the end of the edge, so it is not a strictly linear ramp, but it's close.? So, the specified Trise or Tfall works for approximately the 0% to 97% or 99% points (on the cases I tried -- it depends on risetime).? But the slope over most of the edge fits as if it were 0% to 100%. ? Regards, Andy ? |
|
Re: I'm ready to give up LTC all toghether.
John wrote: ? ?"The formal definitions of rise time and fall time relate to 10 % and 90 % of the amplitude, because it's not possible to say precisely when the pulse is no longer 0 % and when it first reaches 100 %." That is correct for the method to use to measure rise time and fall time in the lab, where real signals are not straight with sharp corners. But for generating step waveforms in SPICE, the prescribed rise and fall times refer to the 0% and 100% points of the waveform edges.? This is the convention that UC/Berkeley adopted when they created SPICE some 40 years ago, and LTspice conforms to that convention. It definitely applies to the PULSE voltage and current source waveforms, and it apparently applies here (to the [Digital] library of A-devices) too.? I just tried it with a NAND gate, and that is what I saw. I did see some curvature in the output waveform, near the end of the edge, so it is not a strictly linear ramp, but it's close.? So, the specified Trise or Tfall works for approximately the 0% to 97% or 99% points (on the cases I tried -- it depends on risetime).? But the slope over most of the edge fits as if it were 0% to 100%. Regards, Andy |
|
Re: Piece-wise voltage signals
spangenbergjack asked about generating a complex waveform with both linear and exponential portions, for which he/she has two sets of Excel data. If I read this correctly, I think your two best choices are: (1) Use Bordodynov's recommendation.? Extract your two PWL data sets into files.? Use two PWL voltage sources in series, and have each one load a PWL file. (2) Since the second pulse has exponential edges, you could fit an EXP voltage source to that pulse.? Then use a PULSE or PWL to fit the first pulse, and again put the two voltage sources in series with one another.? Make sure NOT to use 0 for the rise and fall times. I am confused about having the pulses repeat themselves, since that wasn't in the first description. ? ?"What I'd like to do, is write an exact formula for the above. So far I can write a formula for each single section and make that repeat itself, but I'm at a loss as to how to piece it all together." Piecing or splicing the two pulses together should be a simple matter of math.? Just delay the second pulse enough so it doesn't overlap the first one, and add their formulas together, and now you have a single formula. Once you do come up with a single formula, you can use a B voltage source with that formula, to generate it. Regards, Andy |
|
Re: I'm ready to give up LTC all toghether.
John Woodgate
开云体育The formal definitions of rise time and fall time relate to 10 % and 90 % of the amplitude, because it's not possible to say precisely when the pulse is no longer 0 % and when it first reaches 100 %. ? To find how LTspice interprets them, define a pulse with millisecond values and look at its waveform, with .opt plotwinsize=0. ? With best wishes DESIGN IT IN! OOO – Own Opinions Only J M Woodgate and Associates Rayleigh England ? Sylvae in aeternum manent. ? From: LTspice@... [mailto:LTspice@...] ? ? Replying to a few specific questions from Gunoi Nare: |
|
Re: LTspice XVII binary log files
Several months ago (well before LTspiceXVII), LTspice's text output files (.net, .log, .asc, .asy) did change slightly, from using CR/LF pairs as line-terminators, to using CR only (or was it LF only?). This confuses Windows Notepad, but just about every other text editor could handle them just fine. And then there is Unicode.? What fun.? There used to be a time when plain-text really was plain text.? Notepad is about as dumb as a text editor can be, so you are better off using something else. Andy ? |
|
Re: LTspice XVII Co-exist with LTspice IV?
开云体育In many circumstances you can right click and choose from a range of applications.. ? Dave G4UGM ? From: LTspice@... [mailto:LTspice@...]
Sent: 15 August 2016 18:56 To: [LTspice] group Subject: Re: [LTspice] Re: LTspice XVII Co-exist with LTspice IV? ? What I do, when I want the other version of LTspice to open (instead of the default one), is: ? (1) Start the LTspice that I want to be run, ? (2) Go to Windows Explorer and drag the schematic into the LTspice window. ? Andy ? ? |