LCD Refresh Rate

C

CaptNemo

I know on CRTs the higher the refresh rate, the better.
Is it the same on LCD flat panels? Just got a new one. My lcd (viewsonic
vx910 ... video card is ati x700pro) can be set at either 60 hertz or 70
hertz.
Which one to use?
 
N

Noozer

CaptNemo said:
I know on CRTs the higher the refresh rate, the better.

Nope...not always.

If you set the refresh rate too high it can blur the pixels.
Is it the same on LCD flat panels? Just got a new one. My lcd (viewsonic
vx910 ... video card is ati x700pro) can be set at either 60 hertz or 70
hertz.
Which one to use?

The one that looks better.
 
A

Augustus

CaptNemo said:
I know on CRTs the higher the refresh rate, the better.
Is it the same on LCD flat panels? Just got a new one. My lcd (viewsonic
vx910 ... video card is ati x700pro) can be set at either 60 hertz or 70
hertz.

Every LCD monitor has ONE optimal resolution and refresh rate. Mfgtr's specs
will tell you this. If your run at anything else, visual quality will suffer
a lot.
 
F

First of One

60 Hz is probably the best setting, though it doesn't hurt to try 70 Hz to
see if it gives you better image quality.

The pixels in an LCD change only when the screen content changes. There's no
flicker. With LCD panels you should be looking at pixel response times,
contrast ratios, max brightness, etc.

A CRT's electron beam will scan back and forth *even if the screen content
does not change*, so you need a high refresh rate to eliminate flicker on a
CRT. Even then, once you go higher than 85 Hz, there's no benefit.
 
M

/mel/

CaptNemo said:
I know on CRTs the higher the refresh rate, the better.
Is it the same on LCD flat panels? Just got a new one. My lcd
(viewsonic vx910 ... video card is ati x700pro) can be set at either
60 hertz or 70 hertz.
Which one to use?

70Hz, definitely. Or maybe 60Hz? Yeah, 60Hz I reckon. Probably. But you
might like to try 70Hz, just in case. I bet 70Hz is best. Hmmmm. Tell you
what, why not try both? I imagine you'll be able to tell in less time than
it's taken me to type this.
 
T

Thomas Engler

CaptNemo said:
I know on CRTs the higher the refresh rate, the better.
Is it the same on LCD flat panels? Just got a new one. My lcd (viewsonic
vx910 ... video card is ati x700pro) can be set at either 60 hertz or 70
hertz.
Which one to use?

First of all you should buy a DVI-cable and connect the card to the
monitor via DVI-port. Then you can set the refresh rate to 60Hz and the
picture will be rock stable. Having DVI and not using it is a waste...


Thomas
 
M

Mad Ad

CaptNemo said:
I know on CRTs the higher the refresh rate, the better.
Is it the same on LCD flat panels? Just got a new one. My lcd (viewsonic
vx910 ... video card is ati x700pro) can be set at either 60 hertz or 70
hertz.
Which one to use?


The highest

prolly 75Hz for many 17"-19" tft
 
S

Shawk

Augustus said:
.



Bad answer. The best to use is the native resolution. Which is never 75Hz
for a 17-19" TFT.

Agreed. Native on my 17" is 60Hz and it's rock steady.
 
B

Barry Watzman

You guys are confusing totally different things.

Resolution is number of pixels xxxx horizontally x yyy vertically

Refresh rate is the number of times per second that each pixel is rewritten.

The two have no interdependent relationship, and monitors, while they do
have a "native" resolution, do not have a native refresh rate.

For a progressive scan system (which computers are) there is very little
reason to go above 60 Hz refresh rate. The usual reason for higher
refresh rates are to reduce flicker, but that only applies to CRTs. In
a CRT, at any given instant, only one point on the screen is "lit", that
point "scans" the screen, you perceive seeing the entire screen due to
both the persistance of the screen phosphor and your eye's persistance
of vision. But in a LCD panel, each pixel is "latched" and is
continuously lit, thus there will never be "flicker", at any refresh
rate, no matter how low. And there's not much reason to raise it above
60 Hz, either.
 
A

Augustus

Barry Watzman said:
You guys are confusing totally different things.

Resolution is number of pixels xxxx horizontally x yyy vertically

Refresh rate is the number of times per second that each pixel is
rewritten.

When talking about TFT/LCD screens, it's meant that "native resolution" has
both a specific resolution and a specific refresh rate. For most 17 and 19
inch ones, it's 1280x1024 @ 60Hz. I am aware of the difference between the
two and how LCD/TFT monitors operate vs CRT's.
 
B

Barry Watzman

There's no "native refresh rate", although any given monitor will
support only a limited number of specific video formats (each specifying
refresh rate as one of many parameters).
 
A

Augustus

Barry Watzman said:
There's no "native refresh rate", although any given monitor will support
only a limited number of specific video formats (each specifying refresh
rate as one of many parameters).

You are wrong. LCD/TFT monitors have one optimal refresh rate and
resolution. Every other resolution and refresh is emulated. Read under
"native resolution" heading in this article. Thee are dozens of other
references all saying the same thing.
 
T

Thomas

Andrew said:
On my 15" it is very clear at the maximum of 75, anything less is very
noticeably blurred.

But then, 75 is nothing... My 19" Dell CRT also has a problem on lower
frequencies, even at 85 Hz it's a bit 'shaky'. But well, it will take my
preferred setting; 1280x960 @ 100Hz. It's quite crisp, though at a lower
frequency it's sharper. It's just a bit shaky, very tiresome for my eyes.
 
A

Andrew

But then, 75 is nothing... My 19" Dell CRT also has a problem on lower
frequencies, even at 85 Hz it's a bit 'shaky'. But well, it will take my
preferred setting; 1280x960 @ 100Hz. It's quite crisp, though at a lower
frequency it's sharper. It's just a bit shaky, very tiresome for my eyes.

Get a clue, this is a thread about LCD's where you don't need such
high refresh rates as CRT's.
 
T

Thomas

Andrew said:
Get a clue, this is a thread about LCD's where you don't need such
high refresh rates as CRT's.

Get a clue yourself :) The comment "If you set the refresh rate too high it
can blur the pixels." was about CRT's, not about LCD's... Hence my response
that 75 Hz was not 'too high' for CRT's.
 
A

Andrew

Get a clue yourself :) The comment "If you set the refresh rate too high it
can blur the pixels." was about CRT's, not about LCD's... Hence my response
that 75 Hz was not 'too high' for CRT's.

Again, everyone apart from you is talking about LCD's where the wrong
refresh rate can blur the pixels.
 
T

Thomas

Andrew said:
Again, everyone apart from you is talking about LCD's where the wrong
refresh rate can blur the pixels.

Grr... this is very uninteresting, but let me show you what i replied to:

START
I know on CRTs the higher the refresh rate, the better.
Nope...not always.
If you set the refresh rate too high it can blur the pixels.
FINISH

Tadaaaa.... that's what i replied to, i wasnt the first to mention
CRT's.......................
 
C

Conor

70Hz, definitely. Or maybe 60Hz? Yeah, 60Hz I reckon. Probably. But you
might like to try 70Hz, just in case. I bet 70Hz is best. Hmmmm. Tell you
what, why not try both? I imagine you'll be able to tell in less time than
it's taken me to type this.
BWAHAHAHAHA...

****ING CLUELESS MORON.

Clue: CRT..the "dots" fade. If they're not refreshed then they
disappear altogether.
LCD..the dots stay on until their state is switched.

Therefore refresh rate doesn't matter a jot with LCD.
..
 

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