Monitor refresh rate question

  • Thread starter Thread starter Jitz
  • Start date Start date
J

Jitz

Might be somewhat off topic, but I suspect the video card has something to
do with it......

I recently purchased an LCD monitor with a native resolution of 1280 X 1024
and a max refresh rate of 75. My video card is a Radeon 9500. When I check
the monitor properties, 60 is the max I'm allowed to set it to. Does anyone
know why I can't set to 75?

Thanks.

Jeff
 
Jitz wrote: >
... LCD monitor with a native resolution of 1280 X 1024
and a max refresh rate of 75.
Click to expand...

What is the pixel response time?
When I check the monitor properties, 60 is the max
I'm allowed to set it to. Does anyone know why I can't set to 75?
Click to expand...

It may not matter. CRTs need to run 70 or more to reduce
refresh flicker. LCDs don't flicker at any refresh rate
(unless the content data stream itself does).

Going above 60 on LCD only matters (if it even matters
there) for gamers with fast eyes, fast brains, fast CPUs,
fast graphics and LCDs with credible pixel response
times of 12mS or lower.

I ran my previous 1920x1200 CRT at 85Hz.
I run the replacement 1920x1200 LCD at 60.
 
Might be somewhat off topic, but I suspect the video card has something to
do with it......

I recently purchased an LCD monitor with a native resolution of 1280 X 1024
and a max refresh rate of 75. My video card is a Radeon 9500. When I check
the monitor properties, 60 is the max I'm allowed to set it to. Does anyone
know why I can't set to 75?

Thanks.

Jeff
Click to expand...
Did you install the monitor .inf file?
 
Sean Cousins wrote: >
Did you install the monitor .inf file?
Click to expand...

And be sure to check the brand site before assuming
there isn't one. Some vendors have introduced LCDs
that initially ship with no .inf media, apparently assuming
that the read-back data available via Dsub15 and DVI-D
covers it. It doesn't.

I only recently discovered that an .inf and .icm file were
available for the LCD I bought a year ago. The thing
shipped with a CD-ROM, but there was only documentation
on that disc.
 
Jitz said:
Might be somewhat off topic, but I suspect the video card has something to
do with it......

I recently purchased an LCD monitor with a native resolution of 1280 X
1024 and a max refresh rate of 75. My video card is a Radeon 9500. When I
check the monitor properties, 60 is the max I'm allowed to set it to. Does
anyone know why I can't set to 75?

Thanks.

Jeff
Click to expand...
It's possible that the card is reading the EDID (AKA PnP info) of the
monitor
as having a preferred mode of 12 by 10 at 60Hz. As Bob Niland pointed out,
you really do not need to run an LCD above 60Hz refresh unless it has really
fast response time.
However, you may be able to override the PnP preferences by going into
the
advanced display properties and clicking the "List All Modes" button under
the
ADAPTER tab - see if that gives you refresh rate possibilities.

HTH,
NGA
 
Not Gimpy Anymore wrote: >
... you really do not need to run an LCD above 60Hz refresh
unless it has really fast response time.
Click to expand...

Speaking of fast response time, DigiTimes ran a picture+slug
this week on the Viewsonic VX924:
"ViewSonic showcases its 1 ms LCD monitor at CES,
claiming it as the world's fastest model."

Depending on what site you look at, though, this is
alternatively claimed to be a 2, 3 or even 4mS monitor.

<http://www.digitimes.com/photogallery/ShowPhoto.asp?ID=930&pg=1>
Caution: stories on DigiTimes go from free to subscription
pretty fast.
 
rjn said:
Jitz wrote: >


What is the pixel response time?


It may not matter. CRTs need to run 70 or more to reduce
refresh flicker. LCDs don't flicker at any refresh rate
(unless the content data stream itself does).

Going above 60 on LCD only matters (if it even matters
there) for gamers with fast eyes, fast brains, fast CPUs,
fast graphics and LCDs with credible pixel response
times of 12mS or lower.

I ran my previous 1920x1200 CRT at 85Hz.
I run the replacement 1920x1200 LCD at 60.
Click to expand...

Thanks for the response. The response time of the monitor is 8 ms.

The reason (I think) I'm looking to bump up the refresh rate is that the
screen is very hard on the eyes, mostly when looking at white backgrounds
like a web page.
 
rjn said:
Sean Cousins wrote: >


And be sure to check the brand site before assuming
there isn't one. Some vendors have introduced LCDs
that initially ship with no .inf media, apparently assuming
that the read-back data available via Dsub15 and DVI-D
covers it. It doesn't.

I only recently discovered that an .inf and .icm file were
available for the LCD I bought a year ago. The thing
shipped with a CD-ROM, but there was only documentation
on that disc.
Click to expand...

I haven't yet, but I'll check it out. Thanks.
 
Thanks for the response. The response time of the monitor is 8 ms.

The reason (I think) I'm looking to bump up the refresh rate is that the
screen is very hard on the eyes, mostly when looking at white backgrounds
like a web page.
Click to expand...

And bumping up the refresh rate will help this how?
 
I haven't yet, but I'll check it out. Thanks.
Click to expand...
There's your problem. You are just using XP's default Plug and Play
monitor setting which will only give you 60hz for your LCD. Install
the .inf file and the vid card will know what your monitor is cpapble
of. Persoanlly, I run my LCD at 60hz anyway even though it can do
75hz.
 
I recently purchased an LCD monitor with a native resolution of 1280 X
1024 and a max refresh rate of 75. My video card is a Radeon 9500. When I
check the monitor properties, 60 is the max I'm allowed to set it to.
Does anyone know why I can't set to 75?
Click to expand...

Because the maximum refresh rate depends on the resolution. See
"Control panel > Display > Parameters > Advanced > Adapter > List all
modes"
 
On an LCD monitor, the refresh rate is irrelevant. It does not matter
what you set it to, unlike a CRT monitor. 60 is just fine.

Michael

http://www.protonic.com


___________________________________________________________
 
(e-mail address removed) wrote: >
On an LCD monitor, the refresh rate is irrelevant.
Click to expand...

Only insofar as a higher rate reduces flicker, which
doesn't exist on LCD.
It does not matter what you set it to, unlike a
CRT monitor. 60 is just fine.
Click to expand...

If the LCD has a credible response time under 17mS,
then the displayed pixels can change faster than 60Hz.

But generally, if the panel has a native rate, use it,
particularly if driving it via analog. Sending a faster
signal than can actually be painted in real time
might even result in needless artifacts.
 
rjn said:
If the LCD has a credible response time under 17mS,
then the displayed pixels can change faster than 60Hz.

But generally, if the panel has a native rate, use it,
particularly if driving it via analog. Sending a faster
signal than can actually be painted in real time
might even result in needless artifacts.
Click to expand...
It just isn't that simple - to perceive flicker there has to be enough
modulation for the brain to "see" it, and at 17 mS there simply isn't
that much modulation. You will have to get much faster than the PERIOD
of 60Hz before the modulation becomes significant enough to perceive.
The reason CRT's show flicker up to higher frequencies is that their
response time is on the order of MICROSeconds not milliSeconds.
A "slow" phosphor with 1 or 2 milliSeconds response time is typically
seen as not having perceptible flicker. LCD's will have to get into that
same magnitude before it becomes a concern.

That said, a major LCD monitor marketing company has just tried
to announce one with a 1 mS response time. Problem is there seems
to be uncertainty about how it is measured, and whether it is truly
1, 2, 4 or (??) mS in actuality.

NGA
 
Sending a faster signal than can actually be painted
Not Gimpy Anymore wrote: >
It just isn't that simple - to perceive flicker ...
Click to expand...

True, but I was thinking of sampling artifacts, not flicker.
 
rjn said:
Not Gimpy Anymore wrote: >


True, but I was thinking of sampling artifacts, not flicker.
Click to expand...
OK - Experience with workstation applications tells us that sampling
too fast causes artifacts of blurring, color haloing, & "disappearing
pixels"
(for small details) in the display itself. Faster response displays do
reduce
these artifacts,but the present state is pretty much still where a 60 Hz
refresh is adequate for the image refresh - in a few years we may see the
refresh rates being bumped up for the more demanding applications. I
expect monitors for those kind of applications will still be "high end" and
not "run of the mill" as far as performance & cost. If things are painted
too fast they will never be seen by the user....IMHO (thinking about the
effective sampling rate of we human observers).

NGA
 
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