Qspice : Not Responding

QSPICE
1

Hi,
Sometimes i rum simulation for like 500 seconds. After some time it shows not responding. I am using 64Gb RAM computer. I see 8 waveforms, together in waveform viewer.? I want to run the simulation, till the end , and see the waveforms, but soon as i zoom it or do something, even a minor modification in viewing, it hangs and shows, not responding. What can help?

_
Mike 2

2

Hi, Mike.

Without seeing the circuit, I’d just be guessing. “Not responding” is a bit vague but I presume that you mean that Windows says the process is not responding. That doesn’t mean that the process is actually hung – it merely means that the QSpice process isn’t fetching GUI messages fast enough. Windows thinks that it might be hung. It will likely complete if you have enough patience.

For long running simulations, you might try running QSpice from the command line. It will run much faster that the GUI simulation. For example:

  1. In the GUI, View Netlist,| Save As mynetlist.cir.
  2. In a command prompt in that folder, run “C:\Program Files\QSPICE\QSPICE64.exe” mynetlist.cir which will create mynetlist.qraw.
  3. When the command prompt returns, return to the GUI and File | Open | mynetlist.qraw or double-click on mynetlist.qraw in File Explorer.

–robert

3

Just from your message, it seems like your simulation is storing a huge amount of data in .qraw. How large is your .qraw file during simulation? To manage large data files, you either need patience or you need to find a way to limit the size of the data file to speed up handling. For example, you can use .save to restrict what to save and .option CULLTIME=xxx to limit the saving rate.

4

The size of .qraw file is 509 GB.

5

I believe that based on the file size, you can anticipate that it would be a considerable load for any program to manage. Nowadays, most AAA PC games average around 100-150GB, and your data file is approximately 4-5 times this size.

My recommendation is that you need to consider how to reduce the size of your data file for a switching circuit with long simulation time.

6

@RDunn

i dont understand it. Can you explain in layman terms? in running it in command prompt to make it run faster.

Also i have disabled .option FASTMATH = 0, which will run it on QSPICE80

7

please help me understanding it more clearly. Those .save & .option CULLTIME
@KSKelvin

8

Download my command reference guide in Github. Search .save and CULLTIME and there is explanation.
Qspice - Command Reference Guide by KSKelvin.pdf

1 Like
9

Oops. Open the *.qraw file in the last step. Sorry.

10

It would be helpful if you can guide me how to run QSPICE using command line . @RDunn or direct me to the resources…

Thanks

11

.save command doesnt save differential voltages

For example it will save data for V(n1) but it wont save for V(n2,n1)

12

If you save V(n1) and V(n2), can you get V(n1,n2) back? SPICE save node voltage.

13

What command line steps are you having trouble with?

–robert