rec.autos.simulators

>Here's a snipped version of a post I made some time back on the subject...

>----------------

>"Mama Don't Let Your Replay Files Grow Up to Be Monsters"

><snipped my drivel>

>It seems that GPL doesn't quite like the idea of an 80MB replay file in a
>128MB GPL server, and it had a rather unceremonious way of
>letting us know it.

><more snipped>

>With thanks to Randy [Cassidy of Papyrus], here's part of what he had to
say
>on the subject:

>----

>"From experiments I performed on Win95, it seems that Windows will only
ever
>allow a single running program to have as much as half the physical memory
>in the computer.  This includes the program, its data, and the pieces of
>the operating system that it uses.  Once a program tries to use more than
>this, Windows seems to page other parts of that program (or its data) out
>to disk, even if there are few other demands on memory....

>Using a 64M replay buffer on a 128M system will be well beyond the point at
>which Windows will swap out other parts of GPL as the replay grows.  If
>you're not noticing any significant performance degradation with a replay
>buffer this large, then you'll probably not notice any with an even larger
>replay buffer.  (The parts of GPL that Windows will be swapping out will
>most likely be old replay data anyway).

>Be careful making the replay buffer extremely large, though.  My machine at
>work (PII-400, 128M) often crashed when I tried to save large replays
>(>20M).  If the replay is 64M, GPL 1.0 might ask Windows to write a single
>64M block of memory to disk in one operation.  Windows, or the BIOS, choked
>very badly on this about 80% of the time, leading to a system crash (not
>just a GPL crash).  (The 1.1 patch will address this issue)."

>----

>So our experience now adds an underscore to Randy's cautionary comments.
>We're now back to using 48MB replay buffers, despite earlier discussions
>with others who reported success with replay files as large as 90MB. My
>guess is that if you appear to be having success with a replay buffer that
>large, you just haven't filled it up yet. You have to *host*, not join, a
>long event, capture a lot of graphic effects, and have a large field before
>you fill replay buffers of that magnitude.

>Jack Rambo

>>...is this information as relevant for me playing off-line?

>Yes. The amount of the replay memory allocation used is a function of,
among
>other things, race distance, the number of drivers (AI or otherwise) and
the
>number of graphics effects selected. The only difference I see between
>online fields and comparably-sized AI fields is that the AI tend to produce
>less in the form of smoke, fire, dirt, dust, sparks, and skid marks! :)

>Jack Rambo

>>Is the longer race times a possible cause of system crashes?

>Absolutely! Long races + large fields + huge replay buffer (sometimes) =
GPL
>crash.

>If you're starting to fill a really large replay buffer, duck and cover.
>Until 1.1 is released, I'm settling for 48MB on my 128MB server.

>Jack Rambo