"Nail That Track" Gets Nailed At The Track
or
"Mama Don't Let Your Replay Files Grow Up to Be Monsters"
No, we're not compiling lyrics for a new country music hit based on the
life and times of the online formula jockey. Though certainly we have more
than enough characters and material to fill out a stanza or two! Just trying
to offer our fellow GPL fanatics a word of caution and pay tribute to the
poor souls who are now the subjects of the soon-to-be-released smash hit "I
Put My Heart in The Rouen Finale and They Stomped That Sucker Flat!"
First, the caution:
***** Don't use huge GPL Replay Files! *****
With the NTT Rouen Finale chequered flag in sight for the guys up the road,
who had passed me more times than I could count, I suddenly found myself
trying to steer my way through Netscape Navigator! I didn't know whether to
brake for the File menu, or turn right at the "VROC Setup" hyperlink, if you
know what I mean. 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. (Translation: GPL simply vanished without a trace. You
know, like "I Held Her, I Loved Her, She Was There, And She Was Gone.")
Ironically, after I had waded through the stack of e-mails from the NTT
racers who quickly apologized for discoing (What a nice polite bunch! Hey,
I won't tell them, if you don't!), I got to an e-mail from Randy Cassidy in
which he suggested that really big replay files might be fraught with
danger. With thanks to Randy, 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.
Finally, I do need to acknowledge all the NTT drivers who had worked so hard
through the hour-long qualifying session and could almost reach out and
touch the finish line when disaster struck. Specifically:
Chris Cavin - Chris had managed to pull away from some of the toughest
competition on the Internet and had completed 17-2/3 laps of the 18-lap
event when "the lights went out."
Pierre Robitaille, Jeff "ViMan" Eiland, and Dave Ewing had all driven
outstanding races and were very much in the mix, vying for spots on the
podium. Perhaps there were a few other contenders who I've missed since my
view of the action was from the other end of the field <g> and unfortunately
there's no replay file from which to compile our traditional race report.
Kudos to all the NTT drivers! See you at Spa on Monday!
Jack Rambo
race report.<<
Or fortunately, if you'd seen the race from my seat. Not exactly a shining
effort; it's good to know it won't be subject to review! Too bad for CC,
though; he was motoring. I suspect he'll be back to haunt us again. :-)
Thanks for the info, Jack!
Steve B.
remove "edy" from address for email
