Long startup for simulations using ADE-XL

Hi Vivek,

First of all, I'd suggest you take a look at Cadence Online Support Solution 11495216. This describes how to optimize the speed of startup of the background process.

The reason a background process is created is for several reasons:

1. To netlist the design
2. To launch the simulation
3. To do the results post-processing.

It might seem like overkill to do this, but the primary reason is that if you are running multiple simulations in parallel (e.g. over a sweep, or corners), you can launch several of these - and they can be distributed on a compute farm (e.g. using LSF). That means that the netlisting and post-processing are not a bottleneck by being done in the foreground process. 

Also, the background process should start up pretty quickly (say, within 10 seconds, if set up properly), and ADE XL will also re-use it for subsequent runs that are done within  the "linger time" (see solution 11575172) - so you don't have to pay this 10 second overhead again and again.

It also does not use additional ADE XL licenses for the background processes (so it is not a money making scam!).

Hope that's clear,

Regards,

Andrew.

 Hi Andrew,

Thanks for replying. I didn't mean to suggest that there was a scam involved, but anyway I see the problem even if I don't understand why it is needed to launch a full cadence session per job.

Anyway, playing with the linger time helps a bit (the default was 5 seconds). As our Cadence sessions take significantly more time than just 10 secs (lots of customization), I probably will check those links you suggest. However, that needs to wait. Our internal Cadence support is on vacation. So I cannot get the details needed to register at Cadence support.

Vivek 

Interesting - I may have guessed who you work for because I recall another customer that had set it to 5 seconds! The default linger time (the Cadence default) is actually 300 seconds which is much more appropriate.

Note that the linger time is the period of inactivity after the simulation has finished. 5 seconds is pretty much pointless, because it means that it will almost never re-use the background session.

Regards,

Andrew.

Thanks! I can imagine some such thing happening, as I am perhaps one of the only 2 people using this tool here as far as I know.

At present, I am setting linger time much higher. But on the same note, is there any way to change the default settings which are loaded by ADE-XL upon startup? I always need to change these things like linger time and the numberof history entries to be saved etc. when I first start ADE-XL?

Thanks,

 Vivek

Hi Vivek,

If you want to have your own default job-setup form , you can refer to the following Online Support Solution :

For having the default number of history entries to be saved you can set the following .cdsenv variable as  :

; to have the default history entries as 6 

adexl.simulation saveLastNHistoryEntries int 6
 

Regards,

Sunil

 Just for the record. I set the linger time to a large value and set the option to prevent .cdsinit from being loaded by each new ADE-XL job, and there is remarkable improvement in the speed now. As a matter of fact, the simulations start immediately in the later runs as the ADE-XL jobs are already running in the background.

At present, this works only locally as distributed jobs are not always started on the same machine for successive runs. However, that's another issue.

Sunil: I did try to set the default history entries to be larger than 3 but it doesn't seem to work. Anyway, I think I can lock previous runs and then they ought to be retained then as locked runs do not count towards the quota of 3 history entries.

 Vivek