Dvi

Quote from TonySanDiego:
I noticed this in the card description
Maximum digital resolution : 1280x1024 24bpp @ 60Mhz per display - Does this mean that 1280 x 1024 is max for digital? What does 24 bpp mean exactly? If I wanted higher than 60hz could I turn the bits per pixel down at the sacrafice of number of colors?

I know it is very important to be able to run CRTs at higher hz or you get flicker. Is this a problem with LCDs or is it acceptable to run them at 60hz?
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It only means that the max for THAT card in digital mode is 1280x1024 - there are digital flat panels with higher resolution than that (although the digital vs. analog debate is mostly overblown)

24bpp = 24 bits per pixel (it's referring to color depth = 16M colors = TrueColor)

60 Hz should be fine for an LCD - flicker on a CRT is usually caused by an interaction between the CRT scan and overhead lights - have never seen a LCD flicker.

Also - for the LCD itself - most people don't notice any difference between a quality analog vs. digital panel. LCD response time is more important in producing a quality image (especially if you're looking at rapidly changing images like video) than the "Hz" rating.

The panel itself is generally more important than the video card specs (the image from a 1280x1024x24 card from ATI will usually be as good as that of a 1280x1024x24 card from Matrox).

To compare panel display quality, here are a few things to try:

1. Display an all white screen and then an all black screen - look for pixel artifacts on each - too many and you should pass on it

2. Display a high resolution truecolor fine detailed image of your choice and compare image crispness (panel resolution is not the sole factor determining image quality)

3. Display a text document with 6 point typeface and compare the crispness of the text (some panels (just as some monitors) don't actually display the full # of vertical lines of resolution they're quoted as handling) - if 6 point type isn't crystal clear at the resolution you plan to run it at, you probably don't want that panel

4. Play a DVD movie on the panels - panel response time can be over 30 ms in some cases - the amount of bluring during quick changing scenes increases as the response time of the panel increases
 
Quote from ArchAngel:

60 Hz should be fine for an LCD - flicker on a CRT is usually caused by an interaction between the CRT scan and overhead lights - have never seen a LCD flicker.
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CRT flicker is caused by the electron gun scanning the tube's phosphor surface. The higher the refresh rate the less apparent it is.

LCD's backlights, while flourescent, are powered by special power supplies that run at much higher frequencies than line voltage so flicker is not noticeable.
 
I must say that some of the best "postings" on ET have been the ones in the Hardware and Software Forums. No overblown EGO's to contend with. Just simple, straightforward info!

These Forums have been without a doubt, the most helpful.
You guys are DA BEST !!!

:cool:
 
Quote from waggie945:

I must say that some of the best "postings" on ET have been the ones in the Hardware and Software Forums. No overblown EGO's to contend with. Just simple, straightforward info!
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My LCDs are bigger than yours! I have 21 screens on 16 machines, fed by T1 lines and have 200-day battery backup; how many have you? LOL

It never ends. :D
 
Quote from Tech Analysis:

CRT flicker is caused by the electron gun scanning the tube's phosphor surface. The higher the refresh rate the less apparent it is.
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Flicker is not "caused" but the electron gun scan. If it were, you'd see flickering while looking at the monitor in a dark room (which if you do, then you better have the monitor checked).

Flicker is the result of the visual interaction between the monitor's refresh/scan rate and the frequency of your overhead lighting producing a kind of optical strobing.

Increasing the scan frequency of the monitor alters the synchronization between it and the overhead lighting cycle frequency - reducing/eliminating flicker.

A 60 Hz CRT refresh rate is so often mentioned in complaints about screen flicker because so much room and overhead lighting operates at that same 60 Hz (in the US). However, even at 60 Hz, two people can look at a monitor and one will observe a flicker while the other doesn't see it.

As far as the electron gun and phosphor surface - if the scan rate is too slow relative to the screen phosphor's effective persistance time, you still don't get a "flicker", you tend to see either a subdued lower quality image or a rolling fade-in/out bar.

Since LCDs don't operate like a CRT, the frequency of the analog signal from your video card is effectively irrelavent and you don't see flicker regardless of the surrounding lighting or the signal frequency used.
 
Might want to check out your monitor then (or you peripheral vision :) ). Maybe its got short phosphor persistance that you're catching out the corner of your eye. Or maybe you're perceiving an ocular artifact out of your peripheral vision when you blink.

I just tried dropping the monitor on one of PCs here at a customer site all the way down to 56 Hz with no flicker (and looking at it peripherally made no difference). Checked several others, and they're all running at 60 Hz - no flicker there either.

The last time I saw a monitor flicker was months ago and was one set to 60 Hz in a conference room with lots of flourescent lighting. Stopped when the lights were turned off.

Issue's irrelavent for LCDs anyway.
 
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