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Date:      Sun, 02 Feb 1997 13:48:13 -0800
From:      Amancio Hasty <hasty@rah.star-gate.com>
To:        "Kenneth P. Stox" <ken@stox.pr.mcs.net>
Cc:        multimedia@freebsd.org, hackers@freebsd.org
Subject:   Hardware for video
Message-ID:  <199702022148.NAA02400@rah.star-gate.com>

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It is kind of tricky to get a fast PC nowdays. The issues are 
memory bandwith and PCI bus implementation. The Triton seems to
be well implemented where as the Natoma, found in PPRO, I have
my doubts about.

For instance, I have a P100 / Triton chipset over here and a
PPRO 200MHz / Natoma chipset.

On the PPRO 200MHz , I get a few dma errors while capturing where as
in the P100 I get less dma errors . The condition of both implementations
with respect to video is that I get a better image capture/display at
640x480 32bits 30fps on the P100 than on the PPRO 200MHz.


The PPROs 200MHz are nice for number crunching for instance, metgrab
( http://www.ishiboo.com/~nirva/Projects/metgrab/ )  is a cool
video capture application which does real time video effects however
you need a PPRO for this baby. For applications such as metgrab, 
the more memory bandwith available to the system the better it is.
Unfortunalty, the Natoma chipset does not offer support for SDRAM
and the best that we can do is get 50ns EDO ram.
So for Pentium systems the fastest memory for video operations is
SDRAM. For Pentium PRos with Natoma chipset is 50 ns EDO.

For video capture to disk, is a little bit more tricky because I am not
up to date with the fastest scsi disks. It is almost a safe bet that you 
will need ccd (concatenated disk driver) and more than one disk. You always can 
do "man ccd" to find out more about it.

On the video display side you want something like an S3 968  PCI based
card with VRAM -- a fast video controller coupled with fast memory.

Playing with video applications you can eat up your color palette pretty
quickly so must of the time I run at 32bits with a resolution of 
1024x768 with my Diamond Stealth 64 video (s3 968) with 4MB of memory of VRAM.

Corrections of comments are welcomed.

	Enjoy,
	Amancio








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