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Simulators >> Circuit Simulators >> Spectre simulation with two-cpu Sun
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Message started by jimmy on Mar 11^th, 2004, 10:49am

Title: Spectre simulation with two-cpu Sun
Post by jimmy on Mar 11^th, 2004, 10:49am

Hi all,

Our department has a two-cpu Sun machine. But when a single user runs Spectre on it, there is only one CPU is used. I am wondering if we can setup up something in Cadence so that both CPUs can be utilized to get higher speed.

Thank you so much,
jimmy li

Title: Re: Spectre simulation with two-cpu Sun
Post by Andrew Beckett on Mar 11^th, 2004, 1:54pm

Hi Jimmy,

In IC5033 there is now an option that can allow the
model equation evaluation to be spread over multiple
CPUs. This currently works for bsim3v3 and bsim4 models.

The options are:

multithread=on
nthread=2

(say). See "spectre -h options" for more details.

Remember that many things in a circuit simulator are
essentially sequential, so not that much can be done
in parallel - the model equations is a good candidate
though.

Regards,

Andrew.

Title: Re: Spectre simulation with two-cpu Sun
Post by jimmy on Mar 11^th, 2004, 3:05pm

Thank you, Andew, for your reply.

Do you think it won't help much if we do transient simulation for a switched-capacitor circuit?

jimmy

Title: Re: Spectre simulation with two-cpu Sun
Post by Andrew Beckett on Mar 11^th, 2004, 10:16pm

Jimmy,

It can definitely help - it's not really a function of the type
of circuit. If you have bsim3v3 or bsim4 models, then it
will parallel up the evaluation of the model equations,
regardless of the circuit type.

Now, you have to have at least 512 (I think) devices in
the circuit - so if it is not that large, it will be disabled.

Also, because it is just paralleling up the model equation
evaluation, it won't go twice as fast with a 2 CPU
machine - but you should get some speedup (the
2 threads won't be fully utilized).

Regards,

Andrew.

Title: Re: Spectre simulation with two-cpu Sun
Post by Misha on Apr 8^th, 2004, 6:45am

Hello Andrew,

Is this option only available in 5.0.33? I'm using 5.0.32 and couldn't find it. Is it also available through the AA GUI?

Thanks,
Misha