Re: [simspark-devel] performance

[Yuan X. <xuy...@gm...>]

Hi Hedayat,

You are right. It is only like 2D server, but the latter does not need
so much computation.
As I said in my report about the timer, it depends on the server
performance and hardware.
Currently, some powerful PC can handle the 2v2 game, such as the PC in
the China Open 07.( I do not know the specifies, sorry ). But I am
sure it can not run 11v11. What we can do is optimize the server,
otherwise make the computation time (real time) longer than simulation
time.
However, longer computation time will make game time longer ( it is
not desired by organiger ),
and more important, it is not suitable to the machine learning,
because the experiment is even slower than the real robot.

On the other side, the current server can not run properly in some old computer.
To trade-off, maybe a parameter can imported as `simRate' = simulation
time / real time.
And the user configure it themselves according their hardware. But it
may be hard to newbie.

>  Thanks. But there is a problem (I think), it'll be OK if we are
> occasionally forced to do more than one step in one cycle, but if it happens
> usually which means that the server is unable to finish a single step in the
> desired time (which is the current situation I think), the number of
> required steps will grow exponentially. So what?! I don't know :(
>  Ideally, it shouldn't happen at all or at least in some rare cases, but
> when it happens, the server will not be able to catch up with the time.
>  Things might be better if we call dWorldStep with the real elapsed time
> which will at least prevent accumulation of server delays. (Considering the
> current slowness of the server (at least in my system!), this may change
> nothing at all, but it might be better when the server is optimized a bit?!)
>