Re: pfStats - missing time? (more info)

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Sharon Clay (src++at++rose.asd.sgi.com)
Thu, 16 May 1996 18:42:41 -0700

+>---- On May 15, 8:29am, Simon Gibbs wrote:
> Subject: pfStats - missing time? (more info)
->>
->> I have a simple Performer 2.0 application which includes:
->> pfMultiprocess(PFMP_APPCULLDRAW);
->> pfPhase(PFPHASE_LOCK);
->> pfFrameRate(50.0f);
->>
->> I'm using the default statistics display. In the line:
->>
->> frame=17.5 app=0.3 cull=0.0 draw=6.9
->>
->> What is the meaning of the frame time (and why isn't it
->> the sum of app/cull/draw)?

The frame time is _supposed_ to be your total application latancy
from start of app to end of draw. Unfotunately, we have
a bug in Performer2.0 (and 2.1) and due to a slight reorg of time stamps,
we no longer count the time waiting for the vertical retrace for
swapbuffers to actually happen in the timing.

Since you are single process, you are seeing the time that we must
wait for the previous swapbuffers to be able to start the next draw.
This is that infamous gap in the timing graph before the draw line.

src.

-- 
-----{-----{---++at++   -----{----{---++at++   -----{----{---++at++   -----{----{---++at++
Sharon Rose Clay (Fischler) - Silicon Graphics, Advanced Systems Dev.
src++at++sgi.com  (415) 933 - 1002  FAX: (415) 965 - 2658  MS 8U-590
-----{-----{---++at++   -----{----{---++at++   -----{----{---++at++   -----{----{---++at++

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