Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!hsdndev!cmcl2!phri!rna!dan
From: dan@rna.UUCP (Dan Ts'o)
Newsgroups: comp.windows.ms
Subject: Re: Flicker. . .in 1024x768x256 w/Nec 3D
Message-ID: <1082@rna.UUCP>
Date: 14 Feb 91 04:48:52 GMT
References: <91042.221913MXP122@psuvm.psu.edu> <15085@uudell.dell.com> <12162@ur-cc.UUCP> <15093@uudell.dell.com> <1991Feb13.140718.26550@athena.mit.edu>
Reply-To: dan@rna.UUCP (Root Beer)
Organization: Rockefeller University Neurobiology
Lines: 26

In article <1991Feb13.140718.26550@athena.mit.edu> acook@athena.mit.edu (Andrew R Cook) writes:
)The first is the screen refresh rate, as the gentleman noted above.  If the
)windows driver uses the 60Hz mode, you will percieve a noticable 30Hz 
)flicker.  If you other program puts the card in a 70Hz (yeah!) mdoe, then
)you will see considerably less flicker at 35Hz (15% faster refresh).  The other
)reason for the difference in percieved flicker is what you are looking at on
)the screen.  Windows stuff has a lot of horizontal and vertical lines.  When
)the screen is refreshed every other line, Horizontal lines can appear toflicker
)a lot, especially if they are only 1 pixel wide.

	I believe the ATI VGA Wonder interlaces at 40-some Hz (i.e. 90-some Hz
interlaced). I've found it to be not too objectionable. Like the article
above says, its worse for images that have many line-by-line changes (1-pixel,
1-line different from the next). Another factor not mentioned is intensity.
Flicker is much worse at high brightness/intensity.
	You may find that the ATI card is fast enough to minimize the flicker
that you're experiencing. It would only be a $180 change, rather than replacing
the NEC 3D for a non-interlaced monitor (a very expensive change).


				Cheers,
				Dan Ts'o		212-570-7671
				Dept. Neurobiology	dan@rna.rockefeller.edu
				Rockefeller Univ.	...phri!rna!dan
				1230 York Ave.		tso@rockvax.bitnet
				NY, NY 10021