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Viva slow plotting speed.

Brad RFeng

Hi,

A hb analysis across 18 frequencies, 20 power levels and one resistor over 4 values takes ~3 minutes to complete on a relatively simple amplifier circuit. The Assembler results table has 180 rows. Some of the results are scalar values that appear immediately after the simulation has finished. The other outputs appear in the table as wave icons. The outputs include Pout, Gain, Compression, Current all versus the independent variables. Clicking the plot all with new window icon will send all of the outputs to a new Viva plot window as expected (24 sub windows total) but it takes more than 13 minutes to complete (more than 4X the time required to run the simulation!). To make matters worse the Viva main window and Assembler window are frozen. Dragging any window causes it to be only partially painted/updated and the entire screen becomes a mess.

Do the wave icons in the results table indicate that the waves have been calculated and are sitting in a buffer ready to plot?


Is this slow plotting speed expected and what might be causing such a sluggish response? Can anything be done to improve the performance?

Virtuoso IC61.8-64b.500.27
>uname -r
3.10.0-1160.71.1.el7.x86_64

Regards,

Brad

  • Dear Brad,

    Brad RFeng said:
    A hb analysis across 18 frequencies, 20 power levels and one resistor over 4 values

    I think that represents 1440 simulations in the set. 

    Brad RFeng said:

    Do the wave icons in the results table indicate that the waves have been calculated and are sitting in a buffer ready to plot?


    Is this slow plotting speed expected and what might be causing such a sluggish response? Can anything be done to improve the performance?

    I cannot speak with certainty with respect to the "waves being calculated", but I believe similar to a circuit node that is saved, the data for the waveform is accessible from the simulation database. I would be shocked if the data was stored in Spectre's RAM allocation as some databases can contain 100's of GB.

    I am not sure if you are saving the database locally or from some remote site, but I suspect the added time (and latency in screen updates) relate to the time its requiring to traverse the 1440 simulations within the database. Have you explored writing the data to a local database to see if there might be a difference/

    Just my thoughts Brad...

    Shawn

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