Go Back   nV News Forums > Linux Support Forums > NVIDIA Linux

Newegg Daily Deals

Reply
 
Thread Tools
Old 04-20-10, 04:50 AM   #1
Fenrir
Registered User
 
Join Date: Apr 2010
Posts: 2
Default VSync problem on multi screen setup - Ubuntu 9.10 - GTX285 - 195.36.15 drivers

Hi all,

Here is my current setup :

Ubuntu 9.10
195.36.15 drivers
2 GTX 285 graphic cards (one DVI, one VGA and one HDMI port)
4 screens (2 screens on each cards), all independents (no twinview)
Compiz disabled

On this setup, I have a custom OpenGL application running full-screen on all 4 screens (one application with 4 different contexts, based on the graphical engine OpenSceneGraph). My app is running at 60fps when VSync is on, it's the screens refresh rate.

When I enable "Sync to VBlank" in the Nvidia-settings, here is the current result :
- On the first screen of each cards (plugged on the DVI port), the VSync is perfect, no tearing.
- On the second screen of each cards (plugged on the VGA port), tearing is noticeable on the upper part of the screens (I have a line about 100 pixel far from the top of the screens).
=> Result : 2 screens without tearing, 2 screens with tearing in a specific location.

I have also tested on GTX285 cards with 2 DVI ports with the same result.
Another note : the 4 screens are the same, all plugged in VGA (using an adaptor when plugged in the card DVI ports).

Anyone knows how where this problem comes from ? And any idea how to solve it ?
Thanks in advance for your help.

Best regards,
Fenrir is offline   Reply With Quote
Old 04-21-10, 12:03 PM   #2
jesmith
Registered User
 
Join Date: Mar 2007
Posts: 64
Default Re: VSync problem on multi screen setup - Ubuntu 9.10 - GTX285 - 195.36.15 drivers

You can only sync to one monitor at a time. The fact that two seem to be sync'd is just luck.

This is a hardware thing. It's true of all cards, monitors, etc.
jesmith is offline   Reply With Quote
Old 04-29-10, 06:09 AM   #3
Fenrir
Registered User
 
Join Date: Apr 2010
Posts: 2
Default Re: VSync problem on multi screen setup - Ubuntu 9.10 - GTX285 - 195.36.15 drivers

Sorry but you're wrong, we've configured Xorg to use 2 twinviews on the 4 screens and modified our app to use 2 contexts instead of 4 and we have a perfect VSync at 60Hz on the 4 screens. There is absolutely no tearing.

Cheers,
Fenrir is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 04:09 AM.


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