- May 19, 2011
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A computer I built a few years ago has a very odd problem with dual monitor support.
It had a GeForce 8400 GS PCI-E card in to begin with, one monitor (1024x768) connected via DVI, the other via VGA (I think 1440x900), and all was well for a number of years. Then Microsoft started pushing NVIDIA driver updates as 'important updates' on Windows Update, so on default settings those go on automatically. The new drivers have consistently broken dual monitor support. The second monitor isn't detected and no amount of monitor configuration will convince it to do otherwise.
The poor workaround was to revert to the original driver, which works fine (until the next Windows Update for the NVIDIA drivers). The only detail which seems relevant about this set-up was that the second monitor is detected by Windows as a generic non-pnp monitor (the first is pnp).
I suggested that Windows Update should be set to manual, and the user was instructed to install any important updates except for the NVIDIA ones. What resulted was very likely PEBKAC, and an NVIDIA driver update was installed through Windows Update again.
The solution that seemed to be best to me was to switch away from an NVIDIA graphics card over to ATI. No further features or increased performance were needed so I went for an ATI Radeon HD 5450.
Trying the ATI card resulted in a very similar outcome. The second monitor was detected as non-pnp, but instead of no display, it was utterly garbled at any resolution. At one point Windows popped a message saying that this driver wasn't intended for this version of Windows so now the standard VGA driver will be used (which didn't happen, Aero on the first monitor carried on quite happily).
I suppose it is possible that the second monitor has coincidentally become faulty between the time I previously saw the computer (after installing the old driver, it worked) and today, but I think it's unlikely. I checked for a loose cable connection, disconnected and reconnected, tightening the screws for the sake of thoroughness, but it didn't help.
I took the computer home for testing (it would have been nice to take the second monitor but that wasn't possible). At home I connected two 1024x768 monitors to VGA and DVI to the computer without altering any settings and it worked straight away. Both were detected as pnp monitors.
I'm wondering where to go from here. My first idea is to try a HDMI cable from the graphics card to the second monitor where the computer normally lives, and have a HDMI -> DVI adapter at the monitor's end, but does anyone think that this is going to work? One vague possibility is that the VGA cable to the second monitor is simply too long and while the old NVIDIA driver handles it well enough, perhaps the newer one and the ATI drivers are a little more fussy? I could unmount the second monitor and connect it to the computer via a shorter, known-to-work VGA cable and see what happens. Another idea is to take one of my known-to-work monitors and connect it up via the cable that the second monitor currently uses (where the computer normally lives) to see whether it's possibly a cable problem.
I remember someone on this forum saying that Vista's dual monitor support sucks, but surely that's in the realm of graphics card drivers rather than monitor support?
Thoughts?
It had a GeForce 8400 GS PCI-E card in to begin with, one monitor (1024x768) connected via DVI, the other via VGA (I think 1440x900), and all was well for a number of years. Then Microsoft started pushing NVIDIA driver updates as 'important updates' on Windows Update, so on default settings those go on automatically. The new drivers have consistently broken dual monitor support. The second monitor isn't detected and no amount of monitor configuration will convince it to do otherwise.
The poor workaround was to revert to the original driver, which works fine (until the next Windows Update for the NVIDIA drivers). The only detail which seems relevant about this set-up was that the second monitor is detected by Windows as a generic non-pnp monitor (the first is pnp).
I suggested that Windows Update should be set to manual, and the user was instructed to install any important updates except for the NVIDIA ones. What resulted was very likely PEBKAC, and an NVIDIA driver update was installed through Windows Update again.
The solution that seemed to be best to me was to switch away from an NVIDIA graphics card over to ATI. No further features or increased performance were needed so I went for an ATI Radeon HD 5450.
Trying the ATI card resulted in a very similar outcome. The second monitor was detected as non-pnp, but instead of no display, it was utterly garbled at any resolution. At one point Windows popped a message saying that this driver wasn't intended for this version of Windows so now the standard VGA driver will be used (which didn't happen, Aero on the first monitor carried on quite happily).
I suppose it is possible that the second monitor has coincidentally become faulty between the time I previously saw the computer (after installing the old driver, it worked) and today, but I think it's unlikely. I checked for a loose cable connection, disconnected and reconnected, tightening the screws for the sake of thoroughness, but it didn't help.
I took the computer home for testing (it would have been nice to take the second monitor but that wasn't possible). At home I connected two 1024x768 monitors to VGA and DVI to the computer without altering any settings and it worked straight away. Both were detected as pnp monitors.
I'm wondering where to go from here. My first idea is to try a HDMI cable from the graphics card to the second monitor where the computer normally lives, and have a HDMI -> DVI adapter at the monitor's end, but does anyone think that this is going to work? One vague possibility is that the VGA cable to the second monitor is simply too long and while the old NVIDIA driver handles it well enough, perhaps the newer one and the ATI drivers are a little more fussy? I could unmount the second monitor and connect it to the computer via a shorter, known-to-work VGA cable and see what happens. Another idea is to take one of my known-to-work monitors and connect it up via the cable that the second monitor currently uses (where the computer normally lives) to see whether it's possibly a cable problem.
I remember someone on this forum saying that Vista's dual monitor support sucks, but surely that's in the realm of graphics card drivers rather than monitor support?
Thoughts?
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