Adjusting PC Hyperthreading for Spice Simulation

I wish LTspice would accept the old original MicroSim Schematics as a front-end.

LTspice schematic capture is rather juvenile ;-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | I love to cook with wine Sometimes I even put it in the food

That would be nice, particularly if there was a "Correct Wrong Connections" button ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| 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

In the old days we used an IBM 029 to enter the netlists.

I used to draw schematics with pencil-on-paper, number the nodes, then type up the netlist and Spice commands, then run on a VAX-780 ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| 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

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Well, the LTspice schematic format is well-known/documented... did MicroSim ever publicly document the format of their schematic files? If so then it shouldn't be too difficult to write a converter... if not finding someone to voluntarily reverse-engineer the MicroSim schematic format is probably unlikely...?

Yeah, it is, but you have to remember it's the work of exactly one guy who other duties besides just working on new features/bug fixes for it.

---Joel

I know... I was just "funning" ;-)

I can generate a netlist/cir file using my schematic capture then run in LTspice, but I'd have to enter the node names by hand in the post-processor.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| 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

I never had to use an 029, but I did have to wrap JCL around the netlist to run the sim jobs on the mainframe. Text entry was via

2741s (ruggedized communicating Selectric typewriters) and output via line/chain printers.

I like Orcad pspice. The old microsim pspice also had a good schematics entry. If LTspice had a better user interface it would be a killer.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
                     "If it doesn\'t fit, use a bigger hammer!"
--------------------------------------------------------------

Hello Nico,

I bet that I am faster drawing a schematic for simulation than you or I will do in PSPICE/ORCAD or any other SPICE program. LTspice schematic entry is optimized for SPICE schematics. PSPICE/ORCAD schematic entry is designed for PCB layout requirements which means extra burden if you only want enter a schematic for SPICE. I like the LTspice schematic entry, because it's fast and dedicated for (LT-)SPICE.

Best regards, Helmut

Capture sucks!

I still use it. Love it!

Yep!

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| 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

Still wouldn't help Sloman. It would still display "INSUFFICIENT DATA, TRY GAIN".

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There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.

LTspice schematics entry is just a little unusual, when you come from MicroSim Pspice. Now that I'm used to it, I do indeed find it better. Much better. It's all a matter of personal taste, I suppose.

Jeroen Belleman

Memory access taking hundreds of cycles? Hell not even a dozen.

Task switches take hundreds of clocks assuming no cache misses.

What kills many applications is disk I/O, by taking many tens of thousands to a few millions of clock cycles waiting to complete.

Hyperthreading uses this time in multitasking situations to get more done. There has to be something to be done in order to see any improvement.

Your guesses were so far off as to be laughable.

You must be thinking of 20 years ago.

When you say line/chain printers are specifically limiting to chain printers or are you including drum printers? (or even other technologies)

Chain printers (1403s). They were soon replaced with laser printers (3800s) though.

It depends how fast your RAM is. At one point (I guess around 5 years ago), 350 CPU cycles for a code cache miss was not atypical, but RAM speed has been consistently increasing faster than CPU speed for the last few years.

For a virtual memory cache miss, where you're waiting on disc access, hyperthreading doesn't help. The OS kernel will just do a full task switch (assuming that there's another process/thread to switch to).

To remove a possible source of confusion: cycle "costs" take into account the fact that each core can execute multiple instructions concurrently (superscalar architecture). So a cost of e.g. "100 cycles" refers to a delay in which a sequence of instructions totalling 100 cycles could be executed, not 100 times the CPU clock period.

This is the first i have heard of it taking that long.