eldo_user

Running Eldo
Fast Launch Script for Small Simulations
greater than the -use_proc specification. The number of threads is automatically
adjusted at runtime to obtain the best computation time.
• Linux
When an application is multi-threaded on Linux, the “top” or “ps” operating system
commands may return misleading information, depending on the version of the library
libpthread.so provided with the Linux kernel. Each thread may appear as a separate
process, each of them consuming the same memory resources. You should consider that
the application only uses the resources indicated for one “process.” Do not consider the
addition of all indicated processes, which in reality correspond to the threads.
• Hyper-Threading
Selecting Hyper-Threading is not recommended because in many cases it can slow
down simulation. Hyper-Threading enables two logical CPU cores to be created for each
physical CPU core. However, it does not duplicate the main execution resources.
Simulation is a double precision computation intensive job and as there is basically one
processing unit per CPU core, selecting Hyper-Threading and putting a compute thread
on these logical units will not speed up the simulation. Simulation makes considerable
usage of the cache as well as the memory bandwidth, which becomes more stressed
using threads with Hyper-Threading, but on the other hand due to no additional floating
point units there will be no significant increase of floating operations using these extra
threads.
Related Topics
Tip
See also “Eldo Arguments” in the Eldo Reference Manual.
Invoking Eldo
Eldo Initialization File
Running Multiple Runs
Fast Launch Script for Small Simulations
By default, when simulating very small designs, the time taken by the common AMS script to
check that the environment is compatible can be longer than the simulation itself. To reduce the
time taken to launch Eldo for small simulations, you can use a utility script to create a
replacement Eldo fast launch script, valid for the local machine.
To create a new local fast launch version of Eldo, enter the command:
ams_localize eldo
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Eldo® User's Manual, 15.3