Bernard Leclerc (bleclerc++at++cae.ca)
Wed, 11 Dec 1996 10:39:12 -0500
>
> Perf 2.0 MR, IRIX 5.3, RE2.
>
> We have a 3 pipe system with APP_CULL_DRAW, every process on a 200MHz
CPU
> of it's own. Every process is running comfortably less than ~24msec
> per frame and the system is correctly GenLocked (as far as we can tell).
> Yet despite all of this, it refuses to run at 30Hz.
>
> Timings are:
>
> DRAW: 22, 24, 22ms
> CULL: 7, 10, 7ms
> APP : 10ms (end of pfFrame to pfSync)
> <1ms (end of pfSync to pfFrame)
>
> Unfortunately, we are have very tiny channel sizes and using
> Performer stats is hard. However, careful timing of my own clearly
> reveals that the DRAW processes on pipes 0 and 1 are not starting
> up until well into the frame. This results in them failing to complete
> within 33msec. Pipe 2's DRAW, and all three CULL processes are
> starting at exactly the correct time (very shortly after pfFrame
> returns in APP) but the DRAW processes for pipes 0 and 1 are not
> starting until sometime AFTER their respective cull processes have
> completed since the times for CULL and DRAW taken together exceed
> 33ms, we break frames all the time unless we move to a very
> simple area of the database such that CULL+DRAW can get under 33ms.
>
> We are running with the pfPhase set to LIMIT - FREE_RUN
> seems to do the same thing - and the system locks up completely
> in LOCK to the point that we have to do a stopgfx/startgfx to
> get the system to come back.
>
> I don't think this is a new problem, we have seen it before,
> but managed to 'get away with it' because CULL times were a
> lot smaller.
Steve, I'm experiencing a similar problem with our 2-pipe RE2/MCO. I'm
meeting with the Performer team next week to discuss several problems
including this one. I'll report later with a "good" answer - I hope.
--
Bernard Leclerc CAE Electronics Ltd., 8585 Cote De Liesse
Technical Leader Saint-Laurent, Quebec, Canada, H4L-4X4
3-D Graphics Applications tel: +1 514 341 2000 extension 2275
bleclerc++at++cae.ca fax: +1 514 340 5496
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