Announce: Multi-threaded LTspice

[Mike Engelhardt]

FYI. --Mike

A major update for LTspice was released today.
LTspice IV, formerly known as LTspice/SwitcherCAD III,
features multi-threaded solvers to better utilize
current multi-core processors. Also included are new
SPARSE matrix solvers that deploy self-authoring
code which is assembled and linked on the fly
in order to approach the theoretical flop limit of
current FPU's. Large circuits run ~3 times faster
on quad core processors. Small circuits will run at
about the same speed as the prior version of LTspice.

Developing a parallel processing version of SPICE has
been a long standing challenge in circuit simulation
that has been met with limited commercial success.
LTspice IV reflects a review of the techniques
that have been attempted and implements proprietary
methods that allow it to efficiently parallelize tasks
that require as little as 5µs to run single-threaded in
proportionally less time with additional processing
cores.

LTspice IV requires a CPU at least as recent as
the P4 and Win2K, XP, Vista, x64 variants or Linux.
Support for earlier CPU's or Win95/98/ME is only
through use of LTspice/SwitcherCAD III which is
still available but is not expected to be further
maintained.

 

[Uwe Bonnes]

LTspice IV requires a CPU at least as recent as
the P4 and Win2K, XP, Vista, x64 variants or Linux.

Mike,

is Linux support still through Wine?

Thanks

 

[Mike Engelhardt]

Uwe,

is Linux support still through Wine?

Yes, but now the help system even works. WINE doesn't
handle .chm files correctly, but xchm does. So LTspice,
when running under WINE, tries to out-smart WINE trying
to out-smart Windows and execute the native Linux xchm
from its X-window system installation.

--Mike

 

[qrk]

Can I import PSpice schematics ?

...Jim Thompson

You can run the PSpice generated net lists in LTspice. Probing is a
hassle. It helps if you name nodes you want to probe.

 

[qrk]

Mikey's post processor ain't the greatest either. If he'd fix that
I'd switch, but customers like the nice plots that PSpice produces.

I'm simulating a 10-bit _potentiometric_ DAC right now (at the device
level)... takes PSpice 20 seconds just to netlist... wonder how
LTspice would handle it?

...Jim Thompson

When I go to work, I'll try one of my educational switcher supplies on
a 2 and 8 core system. My first two tries brought up an issue in the
new version 4, but Mike got that fixed in a snap last night. What I've
done in the past, including PSpice, is use GnuPlot (graphing program).
However, that's a lot of work to make plots. There are easier plot
utilities out there, but I'm too lazy to learn another program.

 

[John Devereux]

Uwe,


Yes, but now the help system even works. WINE doesn't
handle .chm files correctly, but xchm does. So LTspice,
when running under WINE, tries to out-smart WINE trying
to out-smart Windows and execute the native Linux xchm
from its X-window system installation.

Actually, help still does not work for me, any idea why?

LTSpice (4.00d) says "Unable to launch Xchm"

xchm is installed as /usr/bin/xchm.

I also tried creating a symlink /usr/bin/Xchm but still no joy.

 

[Mike Engelhardt]

Actually, help still does not work for me, any idea why?

LTSpice (4.00d) says "Unable to launch Xchm"

xchm is installed as /usr/bin/xchm.

I also tried creating a symlink /usr/bin/Xchm but still no joy.

The problem is that there's no organized way for a Windows
app to call a Linux app from WINE. It's a shortcoming of
WINE that the developers refused to address when I brought
it up. The method in LTspice works under my Xubunto set up
and for other people. Sorry you have no luck. I guess its all
part of using GNU software with no warranty.

--Mike

 

[John Devereux]

The problem is that there's no organized way for a Windows
app to call a Linux app from WINE. It's a shortcoming of
WINE that the developers refused to address when I brought
it up. The method in LTspice works under my Xubunto set up
and for other people.

Strange, I would expect my setup to be very similar. My wine
installation does date from many years ago (although regularly
updated), perhaps something is setup wrong.

Sorry you have no luck. I guess its all part of using GNU software
with no warranty.

Now now, no need for that - as if Windows comes with one? Wine does
an amazing job normally, I find it better at running windows software
than windows itself, most of the time!

And many thanks for LTSpice, and for thinking of linux users too.

 

[Mike Engelhardt]

John,

Now now, no need for that - as if Windows comes with one? Wine does
an amazing job normally, I find it better at running windows software
than windows itself, most of the time!

Yeah, well, the problems are (i) WINE can't properly
render LTspice's .chm file and (ii) the WINE developers
refused to and a function that would allow someone
to port to WINE to work around such problems. Now, I'm
not lawyer, but I didn't worry about it too much
because I checked out the license and it said WINE
was not fit for a particular purpose.

--Mike

 

[John Devereux]

John,


Yeah, well, the problems are (i) WINE can't properly
render LTspice's .chm file and (ii) the WINE developers
refused to and a function that would allow someone
to port to WINE to work around such problems. Now, I'm
not lawyer, but I didn't worry about it too much
because I checked out the license and it said WINE
was not fit for a particular purpose.

Oh well, no problem really - I can view the chm file directly with
xchm (as you suggest in the help dialog). Hopefully the wine help
viewer will improve at some point anyway.