DVI / VGA problem

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Neverwhere

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Hello everyone... I'm having an annoying problem on an XP machine. It's running an old 7600GT which has a VGA and DVI port. When I connect an LCD with the VGA cable(analog) everything works fine. However when I try DVI(digital), The monitor gets signal on bootup, ie. I see the BIOS POST messages, and the windows start up progress bar thingie.. but as soon as windows should kick in, it goes blank. No log on screen. At this point... if I plug the vga in, all is fine. So when windows starts it swaps to vga.

When I have both connected at the same time, the monitor source tells me its using VGA(analog) and in the Nvida settings, I don't see an option to change the source anywhere. Latest drivers are installed.

So DVI works before windows...but I cant swap to it in windows.. any ideas?:confused:
 
One more question.. Will I see any benefit from the DVI over the VGA. I've tested this with a SAMSUNG 22" and a LG 24" at different resolutions. Currently VGA on both monitors is working fine at 1080p. Same DVI issue on both.

I was thinking of trying one monitor on DVI, the other on VGA, in a dual monitor setup, then make the DVI primary... but alas I dont have the LG(friends) with me anymore. I'll dig out an old CRT as a last resort to try that.
 
Googling a bit, I see DVI and VGA only really differ in the response time department. It's not a gaming machine, so maybe I should just stick with the VGA cable..
 
Some graphics cards don't allow for dual view meaning you have to chose your prefered option.

Ready up on your GPU & see what it allows.
 
Neverwhere said:
Googling a bit, I see DVI and VGA only really differ in the response time department.
Click to expand...
That and signal quality, VGA is analogue, so the signal degrades as it moves from the computer to the screen. Perceptually I doubt people can tell the difference however. DVI is digitally and therefore the signal does not degrade. Same for HDMi.

Lastly, because VGA is analogue you'll notice things like screen position must be "auto adjusted" on DVI that is not a problem as the signal is received in it's digital format and the meta-data of the stream is known to the monitor (analogue that information must be inferred, so to speak).

DVI is superior to VGA, but you likely won't notice the difference.
 
You will definitely notice the difference between DVI & VGA when you run your screen at 90' angle - or at least I did.
The major advantage is that you don't have to "auto adjust" your screen with DVI/HDMI like you have to do with VGA.

Perhaps it's just some kind of setting in Windows that disables your DVI output.
 
Thanks guys. I'm using the VGA at 1080p and it looks great. Game had these Samsung P2250's for R999. I see they're normally around R1600, so I decided to replace the CRT on an old system. It's mostly used for browsing and I leave torrents running on it from time to time, so I guess the little difference that DVI will give wont matter. It's an awesome screen though for R999. I had the LG 24" connected to test for a bit, and after swapping to the Samsung, It didnt even feel much smaller because of the 1080p.
 
Compare VGA and DVI in 1080p side by side and you'll notice the difference. VGA is more blurry than DVI.

I experienced the same problem as you once, but I can't really remember what I did. Since DVI works fine during POST, I'm guessing that the problem is with the screen resolution since POST runs at 800x600 (unless I'm mistaken). Try booting Windows using 800x600 - There should be such an option in the Windows Startup Options. I think you need to hit F8 just before windows boots to get to Windows Startup Options.
 
Yes It's the screen resolution, try changing the resolution to the maximum allowable/viewable with the VGA plugged in, once resolution changed, remove VGA and connect the DVI cable.
 
What I've found from googling that it's a timing issue with older cards. The older nVidia chips have something called a pixel clock limit which is fixed at 150MHz max. High res LCD monitors using DVI want more than this. (I too have no problems with VGA, but am limited to 1600 horizontal with DVI in both XP and Linux.)
 
I dunno about no timing issue, but my GeForce 7300 LE runs perfectly fine while playing 1080p content. Then again, what do I know about graphics cards?
 
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