Why does my second monitor flicker a little?

[balane]

I just added a second monitor to my set up. It was no longer being used so I figure what the heck, would be cool.

My primary monitor is a i-inc iH282. 28" It's running landscape at 1920x1200. It's connected to my HD 5870 via a cable with DVI on one end and HDMI on the monitor end. This monitor has never, and currently is giving me no issues connected this way. It looks great.

The secondary monitor I just added, however, is giving me trouble.

It is a Dell IN1910N 18.5" LCD. It only has an Analog D-Sub connector on it. I'm using an adapter on the computer end of the cable from the DVI output on the 5870 and then a 15 pin dsub cable between the adapter and the monitor.

This second monitor is running in Portrait mode, snugged up against the right side of the 28" LCD.

When the computer is sitting still there are no problems but when I start to do something that creates screen movement on the 28" LCD I will occasionally get a flash of a black vertical line on the Dell in portrait mode. (Really it would be a horizontal line as far as the monitor is concerned but to me it is viewed as vertical.) Just a quick flash of a thick (15 pixel or so.) black line and then it's gone. It can appear in any location on the 2nd monitor, seems random.

The 18.5" Dell LCD runs and works perfectly if its used alone.

Seems like a refresh rate problem maybe? Both are locked at 60Hz and I don't seem to have any other adjustments for refresh under settings.

Please help me if you can. Thanks.

 

[balane]

 

[happy medium]

Drivers that are not clocking your card high enough. That was my problem.
Manually overclock your card.or update to the latest drivers.

 

[Idontcare]

Happy, so is this why both NV and AMD cards won't fully idle (use more power at idle) when they have two or more displays connected to them?

Is this what the driver guys are trying to avoid by keeping those idle clocks higher than when a single display is connected? (intermittant synchronization artifacts?)

 

[balane]

It seems to be getting worse.

I have my BIOS flashed on the 5870 to 900/1300 and I'm using the latest drivers from ATI.

Damn thing is driving me crazy.

 

[Idontcare]

Could it be that your monitor is dying?

I had an LCD die a slow death on me once and it was very frustrating to debug because I so badly wanted to believe it was software (cheaper/easier to change and fix) but finally the LCD just died.

Then I realized I had a second identical LCD still in my basement, threw it on the same rig without changing a thing and sure enough it worked fine.

I hope it isn't your LCD, that would be spendy to replace, but you might be pulling your hair out trying to fix a video card that isn't actually broken to begin with.

 

[balane]

I actually wouldn't mind it being the monitor but the fact that it only does this when there is activity on the primary screen really leads me to believe some kind of conflict is occurring. I did plug in an old CRT monitor, however, and it had no issues. I'm just going to remove the second panel and be done with it. I only plugged it in for funnsies anyway, I never really needed it.

 

[ZombieRitual]

I'm having this problem too. Just upgraded from a Sapphire x1950xt to a Gigabyte 5850 (factory OC'd: http://www.newegg.com/Product/Produc...-318-_-Product) and I'm now having the same problem on my second monitor, a Dell 2005fpw in landscape. My desktop is extended onto it from my 23.6" Asus monitor. I have the latest drivers and this only started occurring after installing my 5850 a few hours ago.
Both my monitors are connected via DVI.

 

[Grooveriding]

This problem is related to having more than one monitor plugged into your card.

Because these cards downclock when not being used to game, once you connect a second monitor, due to the downclocking you will get a flicker effect on one of your screens.

It occurs on AMD and Nvidia cards they both solve the issue by not fully downclocking when idle when there are two or more monitors connected.

I had the same problem with my 5870s and it was fixed in a driver update. If you are using the latest drivers, then I believe overclocking the cards can cause the effect to return in certain situations.

If you use Afterburner to overclock the easiest thing is to set up a 2D/3D profile. Have the 3D profile set to whatever your overclock is and the 2D profile set to something that keeps the ram over 700mhz or so.

You can also disable the powersaving functionality via the registry.

Search for something along the lines of 'EnableULPS' and change it to 0 from 1.

 

[Tempered81]

DO like grooveriding suggested and make a 2d profile with higher clocks. Ideally you want more voltage in idle/2d and your memory to remain the same speed in idle/2d/3d (1200mhz for your 5870, op).

Keep the memory from clock gating and it wont flicker, but you will use more power.

There are lots of ways to do this.... Bypass Powerplay, use amdgpuclocktool, or afterburner with enable unofficialoverclockingmethod... Make your own custom bios, hardmod, etc... Try to keep your memory at 1200mhz, if it doesn't help you could try keeping your core from never going to ~157mhz - keep it around 400-600 in 2d.

Lastly, there is an updated bios - your card may have one of the original bioses. There are bioses from sapphire and xfx and asus and ati. You can check techpowerups vga bios collection for all the more modern bioses. Just make sure you dont flash with a 2gb or non-reference bios.

 

[ZombieRitual]

This problem is related to having more than one monitor plugged into your card.

Because these cards downclock when not being used to game, once you connect a second monitor, due to the downclocking you will get a flicker effect on one of your screens.

It occurs on AMD and Nvidia cards they both solve the issue by not fully downclocking when idle when there are two or more monitors connected.

I had the same problem with my 5870s and it was fixed in a driver update. If you are using the latest drivers, then I believe overclocking the cards can cause the effect to return in certain situations.

Even with a factory OC? I haven't done any OCing myself, it came OC'd a bit by Gigabyte out of the box. Should I try to "underclock" it some?

 

[balane]

My OC is done via a BIOS flash. I edited the values manually and altered only the gaming clocks. I'll look into this, at least I have an avenue to go down now.

I'll just shut powerplay off all together if I have to. My stuff runs cool and I upgrade every 18 months anyway.

Thanks for the tips.

 

[balane]

Search for something along the lines of 'EnableULPS' and change it to 0 from 1.

Wouldn't I want to disable this by changing a 1 to a 0? I've never edited mine before and it's on 1 as it sits now, without making any changes.

Just asking to be sure. Cheers.

 

[Grooveriding]

Wouldn't I want to disable this by changing a 1 to a 0? I've never edited mine before and it's on 1 as it sits now, without making any changes.

Just asking to be sure. Cheers.

Yes change the 1 to a 0. When I did this, the cards would still downclock but not to the extremely low levels they did. It was a bit more conservative.

 

[ZombieRitual]

Where would I access my registry in Vista 64? I don't fiddle with the registry and I want to make sure I'm accessing it properly.

 

[balane]

Just type REGEDIT in the Run command field and press enter. Or do a search in Windows for regedit.exe and click it.

 

[coreyman]

Not sure if you have tried this but there is an option in CCC under Digital Panel Properties, i had to uncheck "Alternate DVI operational Mode" and the flicker stopped. There maybe something with the signal from the Card to the Monitor. As well you can try "Reduce DVI frequency on high-resolution displays" I have head this works with some.

 

[LoneNinja]

I've seen ATI Overdrive cause this type of flickering on the 2nd monitor before, if your currently using it, I would recommend to try disabling it.

 

[balane]

Not sure if you have tried this but there is an option in CCC under Digital Panel Properties, i had to uncheck "Alternate DVI operational Mode" and the flicker stopped. There maybe something with the signal from the Card to the Monitor. As well you can try "Reduce DVI frequency on high-resolution displays" I have head this works with some.

I would love to try this but can't find it. I've been through every window of CCC looking for anything that says either Digital Panel Properties or Alternate DVI Operational Mode and can find neither.

Can you please tell me where to locate this setting? Thanks.

Overdrive is off.