nV News Forums


nV News Forums (http://www.nvnews.net/vbulletin/index.php)
-   NVIDIA Linux (http://www.nvnews.net/vbulletin/forumdisplay.php?f=14)
-   -   Sync problems on 2nd twinview DFP display (http://www.nvnews.net/vbulletin/showthread.php?t=95184)

racalac 07-19-07 04:09 PM

Sync problems on 2nd twinview DFP display
Hi, I'm looking for some insight into this problem. I'm especially interested if nVidia has tested this configuration.
One Geforce 880GTS
Two Dell 3007WFP 30" Flat-panel displays connected with Dual-Link DVI cables (confirmed by looking at the full array of pins)
Intel Core 2 Duo, Redhat Enterprise Linux 4 WS update 5 (64-bit)

I have the two displays set up with TwinView oriented top and bottom, with Xinerama enabled. Always on the "second" monitor (plugged into the right-hand DVI port on the card when viewing it from behind) there is sometimes graphical corruption/artifacts/sync problems. It's hard to describe, but if you imagine the display made up of many "columns" of pixels, the columns seem to be interleaved in a strange way.. like if normally you'd see ABCDEF, it appears as BADCFE. Sometimes the "rows" of the screen shimmer or shake left-to-right, like there are some sync problems. If I reverse the cables, the problem moves to the other monitor. I have an identical setup that also has the same problem, so I don't think the displays, cables, or cards have some individual problem. Remember this happens often, but not all the time. Sometimes the second monitor will look fine. If I kill X, or simply switch to a text console (ctrl-alt-1, then ctrl-alt-7) and back I can sometimes see these graphical errors.

I've tried Linux drivers 1-9755 and 100.14.11 both with the same effect.

My xorg.conf is a pretty vanilla TwinView config. here's the device section

Section "Device"

        Identifier  "Videocard0"
        Driver      "nvidia"
        VendorName  "vendor nVidia"
        BoardName  "Nvidia 8800 GTS"
        BusID      "PCI:01:0:0"
        Screen      0
        Option            "TwinView" "True"
        Option      "DynamicTwinView" "False"
        Option      "MetaModes" "2560x1600 +0+1600, 2560x1600 +0+0"
        Option      "AllowDDCCI" "True"
        Option      "ConnectedMonitor" "DFP,DFP"
        Option      "TwinViewXineramaInfoOrder" "DFP-1,DFP-0"


Is there a known issue with the 8800 GTS (or similar) that means it can't drive two 2560x1600 displays with TwinView? my Xorg.0.log doesn't show anything immediately wrong...


(II) Setting vga for screen 0.
(**) NVIDIA(0): Depth 24, (--) framebuffer bpp 32
(==) NVIDIA(0): RGB weight 888
(==) NVIDIA(0): Default visual is TrueColor
(==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)
(**) NVIDIA(0): Option "ConnectedMonitor" "DFP,DFP"
(**) NVIDIA(0): Option "TwinView" "True"
(**) NVIDIA(0): Option "MetaModes" "2560x1600 +0+1600, 2560x1600 +0+0"
(**) NVIDIA(0): Option "TwinViewXineramaInfoOrder" "DFP-1,DFP-0"
(**) NVIDIA(0): Option "AllowDDCCI" "True"
(**) NVIDIA(0): Option "DynamicTwinView" "False"
(**) NVIDIA(0): Enabling RENDER acceleration
(**) NVIDIA(0): TwinView enabled
(**) NVIDIA(0): ConnectedMonitor string: "DFP,DFP"
(II) NVIDIA(0): NVIDIA GPU GeForce 8800 GTS at PCI:1:0:0 (GPU-0)
(--) NVIDIA(0): Memory: 655360 kBytes
(--) NVIDIA(0): VideoBIOS:
(II) NVIDIA(0): Detected PCI Express Link width: 16X
(--) NVIDIA(0): Interlaced video modes are supported on this GPU
(--) NVIDIA(0): Connected display device(s) on GeForce 8800 GTS at PCI:1:0:0:
(--) NVIDIA(0):    DELL3007WFPHC (DFP-0)
(--) NVIDIA(0):    DELL3007WFPHC (DFP-1)
(--) NVIDIA(0): DELL3007WFPHC (DFP-0): 330.0 MHz maximum pixel clock
(--) NVIDIA(0): DELL3007WFPHC (DFP-0): Internal Dual Link TMDS
(--) NVIDIA(0): DELL3007WFPHC (DFP-1): 330.0 MHz maximum pixel clock
(--) NVIDIA(0): DELL3007WFPHC (DFP-1): Internal Dual Link TMDS
(II) NVIDIA(0): Assigned Display Devices: DFP-0, DFP-1
(II) NVIDIA(0): Validated modes:
(II) NVIDIA(0):    "2560x1600+0+1600,2560x1600+0+0"
(II) NVIDIA(0): Virtual screen size determined to be 2560 x 3200
(--) NVIDIA(0): DPI set to (101, 101); computed from "UseEdidDpi" X config
(--) NVIDIA(0):    option

My instincts say "sync problems" given what I see on the second monitor. nvidia-settings -q RefreshRate tells me 59.86 Hz for both monitors. I've gone through the whole nvidia README and haven't found any settings that help.

Any ideas?

netllama 07-19-07 04:11 PM

Re: Sync problems on 2nd twinview DFP display
This is a known bug which will be fixed in a future driver release.

holoman 08-03-07 01:44 AM

Re: Sync problems on 2nd twinview DFP display
Have exactly the same setup (but 8800GTX), and the most prominent problem here is that one of the screens start flashing after a while. Over time it flashes more and more frequently. A reboot fixes it for some time.

Really look forward to the fix, hope it makes into the next release.



All times are GMT -5. The time now is 11:42 AM.

Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright 1998 - 2014, nV News.