Re: [Gems-users] GEMS Simulator Simulation time

[Mike Marty <mikem@xxxxxxxxxxx>]

As Dan said, slowdown is significant with timing models.  When Ruby is
used for timing on top of Simics, we see a slowdown of 10x or so.

Things to watch out for:

 -- Make sure your host machine is not paging.  Simics should be cranking
away at 100% of the CPU time

 -- Make sure that Opal and Ruby are compiled with optimizations.  O2 or
better.

 -- Try setting the memory latency of Ruby to a very low value to see if
this speeds things up.  Of course you may not want to simulate a fast
memory latency



Mike



> Dear Sirs,
>  I am a student using GEMS in a Parallel computing architecture course. I am
> using SIMICS and a SIMICS suse 7.3 image running on a X86 dual processor
> server.
>  The problem I am facing is that when using Ruby for simulation, the
> simulation is extremely slow. Ex- a simple simulation of Unixbech, that
> takes SIMICS about 1 -2 minutes to emulate, takes SIMICS with Ruby about 10+
> hours. Is this kind of slowdown natural ? Is there anything I can do to
> speed things up ? I need to get these results done for my course work,
>  Any help will be greatly appreciated.
> Thanks,
> Hrishikesh Das.
>  Graduate Student,
> Mississippi State University.
>