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Discussion Starter #1

recently i noticed newer graphics cards have only one DVI-I (as opposed to 2) and one DVI-D on them ex: Geforce 600 series and newer

 

the thing is for me i run two Trinitron CRTs, i have been wanting to upgrade my graphics card from my GTX 570 to a GTX 670 or 760, however i am stuck because i need to find a Display Port to VGA adapter that works well, most only go up to 1920x1080 or 1920x1200

 

but i need to support at least 1920x1440 at 85Hz, maybe even 2048x1536 at 85hz (i plan to get a GDM-F520 if i can find one

 

i have also seen them say 24-bit color on adapters, but on my computer it says i am running at 32bpp 32-bit color

 

is there any difference between a Display port to VGA adapter and a DVI-I to VGA adapter in color quality? will my picture look the same, better or worse?

 

also can CRTs display 32bit color or 30 bits (8 bits per pixel) and is there any way to get something that can convert to that?
 

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Yes, the easiest thing to do is to get a cheap (~$5) passive DisplayPort to Mini-DisplayPort adaptor and one of the ubiquitous Apple (or third-party knockoff) MiniDP to VGA adaptors. I would recommend going with the Apple ones as these are active adaptors which actually have DACs and CRTCs in them, so quality is important. Even the Apple ones were about $30 last I checked.


The only downside is that if your monitor supports very high resolutions and refresh rates (e.g. [email protected] or so) you may not be able to use combinations of high resolution and high refresh rate, as the CRTC in the adaptor is not as good as the ones in most graphics cards.


As for color depth, CRTs are fully analog and don't have an inherent color depth. The color depth is a feature of the DAC, which is part of your graphics card (or digital to VGA adpater). I don't know exactly what color depths are supported by the Apple adapters.
 

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Discussion Starter #3

well if it cant due high resolutions at high refresh rates i wont even consider it.

 

interesting, be nice if someone made a high bit depth DAC and display port to VGA adapter for VGA
 

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I've got a friend with a nice NEC CRT, a GPU with a DisplayPort output, and the two adaptors I mentioned. I've never tested them all together, but if I have a chance, I'll give it a shot and let you know what refresh rate/resolution/color depth combinations it supports. (The CRT will happily do [email protected]5Hz when driven from a DVI-I port on a GPU.)
 

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Discussion Starter #5

thank you for your help :) please let me know, i would love to be able to upgrade my graphics without having to buy 2 graphics cards (or 3 for 3 monitors)
 

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Yes, sorry, I forgot to post the results. It probably won't work for your purposes. I don't recall exactly but I think it maxed out somewhere around 1440x1080.
 

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Discussion Starter #8
well darn, that totaly sucks, guess i will have to buy two new graphics cards instead of just one and heat my room up a tone

or get rich enough to make my own adapter or SED/FED monitors
 

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The very best standalone DACs will max out at around 1200 progressive lines. And for "HD" use everyone is most interested in 1080p so a lot of them stop there. High sync rates are out with these, and so are the higher resolutions they can use. I have three 22" CRT monitors that can go at least as high as 2400x1800 @ 60Hz, so the day I upgrade to anything newer I won't be able to use my monitor to its full potential any longer.
 

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Discussion Starter #10 (Edited)
i came up with a unique solution today

it started with seeing this:
http://www.analog.com/en/digital-to-analog-converters/da-converters/adv7123/products/product.html

first i was going to ask the manufactuer how much it would cost for a 400MHz one, but then i got thinking, what if i could somehow combine 2 of these on a display port link, each outputting half of the screen 960x1440 or 1920x720 and somehow mixing the two signals together for 1920x1440, or just two display port to VGA adapters.

i would use something like this for the mixing:
http://www.ambery.com/duvgadvipipv.html

the trick though would be to convince Windows that the dual display port to VGA adapters are actually one monitor, so using a setup like this for triple monitor gaming would not be possible, but it might just work, of course i am wondering if i would loose on some response time.

-edit 1: nevermind, max output is 1920x1200, have to look for some other mixer

-edit 2: something like this, but it is too expensive http://www.bhphotovideo.com/c/product/816200-REG/Apantac_DE_4_Tahoma_DE_4_Multiviewer.html
 
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