Large netlist simulation on linux

[advaitha]

I am trying to simulate a large (>100K elements) post-layout parasitc netlist. The only tool available to me is Cadence Spectre. The system being used has 8GB RAM and runs on 2 Xeon processors at 2.7GHz each. The System monitor shows that the Spectre process uses only upto a little more than 3GB of RAM and then returns the error 'Insufficient memory'.
Can anyone suggest a method to eliminate this error and finish the simulation?

 

[bastos4321]

I am trying to simulate a large (>100K elements) post-layout parasitc netlist. The only tool available to me is Cadence Spectre. The system being used has 8GB RAM and runs on 2 Xeon processors at 2.7GHz each. The System monitor shows that the Spectre process uses only upto a little more than 3GB of RAM and then returns the error 'Insufficient memory'.
Can anyone suggest a method to eliminate this error and finish the simulation?

Use instead Hsim or Nanosim. It uses the RAM much more eficiently. 100k elements for Hsim is peace of cake in less than 1G.


Bastos

 

[kwkam]

What version linux you current use? Some of them can only address maximum 3GB of memory. To reduce the memory required, you better choose to capture some node's voltage and current only. Rather than save all node.

 

[advaitha]

The linux I'm using is Redhat 8.0 ( Kernel version bigmem-2.4.20-28.7.i686 ).

UltraSim/Nanosim are not available to me right now.
Thank you for your suggestions.

 

[treebear]

You'd better use Fedora Core 3 or 4.

Also check your version number of Cadence Spectre. A new one is better.

 

[sunking]

the file is too big for post layout simulation. The speed is very slow even you can read all them to the system.
the best method is omit some small cap(such as below 1fF) and res(such as below 1mOhm).

 

[maui]

advaitha,

On a 32 bit system (IA32/0x86) the computer can only reference 4Gig of memory(2^32= 4,294,967,296 bytes = 4Gig).
Linux and other operating systems are smart and set it up so each program can adress their own 4gig of memory(using virtual memory). I think however that in Linux that 4 gig is split into 3 for program and 1 for Kernel. I think there are kernel options to change the split but not sure about it.
The only way to have one program to reference more than 4Gig of memory is to use a 64bit CPU and OS (2^64 > 4Gig).

So you must either reduce memory usage, or change computer arcatecture.

Maui