tjr@cbnewsc.att.com (thomas.j.roberts) (03/18/91)
I have noticed that my eyes were tired A LOT more often lately, and had
attributed it to merely getting older. I believe I have found a direct
cause - the flicker on my VGA monitor. Many (most ?) people do not see
any flicker on a standard VGA monitor refreshed at 60 Hz (vertical sync
rate); I notice it, but had felt that I could live with it - it wasn't
really very noticeable.
I see the flicker as an intensity variation of the overall
screen - it is most noticeable when the screen has a large
white background or when I see the screen out of the side
corner or bottom of my eye's field of view. Windows is unuseable
for me, unless I change all background colors to black.
I estimate that the flicker I see from a 60 Hz non-interlaced
screen is about 10 Hz - it is clearly nowhere near 60 Hz -
I assume that there is some complicated sort of aliasing going on.
This is not a new observation - just a realization on my part that I
am affected. Note that Eurpoean ergonomic standards require a refresh
rate > 70 Hz (I don't know the exact requirement, but 60 Hz is definitely
not allowed).
My solution - I purchased a Gateway-2000 PC with a Diamond SpeedStar
SVGA card (uses the Tseng Labs ET4000AX chip); I upgraded to a Sony 1304
Monitor. This combination will use a vertical scan rate of 72 Hz
(non-interlaced) in VGA and 800x600 modes; it will also use 60 Hz
interlaced for 1024x768 (which has a noticeable flicker for me). I can
now run Windows without any visible flicker, and have used the system for
> 4 hours in one sitting without problems. This is not the only SVGA
card that can use 72 Hz modes, but this is the most affordable monitor
I have been able to find that can - especially in 800x600. It looks Great!
Tom Roberts
att!ihlpl!tjrob TJROB@IHLPL.ATT.COMhp0p+@andrew.cmu.edu (Hokkun Pang) (03/18/91)
I guess my eye is just as sensitive as yours. I recently started using 640x400 at 70hz instead of 800x600 at 60hz just for that reason. although i see noticeable improvements, but flickering is still quite noticeable even when using a more gentle color scheme. my monitor is capable of operating 800x600 non-interlaced at 90hz, is there any graphics card that take advantage of that? PS. Gateway 2000 owners with VGA 1024 can get upgrade to VGA Wonder Plus for $99 dollar directly from ATI. VGA Wonder Plus comes with a mouse and operates at 70hz for all modes. I'm waiting for it and planning to sell my MS mouse. :-)
eda@persoft.com (Ed Almasy) (03/19/91)
In article <Ybt50zS00Wg185Q20l@andrew.cmu.edu> hp0p+@andrew.cmu.edu (Hokkun Pang) writes: >PS. Gateway 2000 owners with VGA 1024 can get upgrade to VGA Wonder Plus for >$99 dollar directly from ATI. VGA Wonder Plus comes with a mouse and operates >at 70hz for all modes. I'm waiting for it and planning to sell my MS mouse. :-) I have a NEC MultiSync 3D. Please forgive my ignorance, but do you know if it would support the 70mhz refresh rate supplied by the Wonder Plus? Also, is there any special protocol that we have to go through to get the upgrade from ATI?