Nvidia doesn't vsync when using a rotated screen - any ideas?

[BlackStar]

I bought myself a lovely Dell U2311h monitor for Christmas. Great monitor, 23'', IPS, good response times, no input lag, solid build. More importantly, this monitor has a great pivot function that gives you 1920 vertical pixels for trolling on Phoronix - perfect!

Unfortunately, this is where the problems start.

First issue: Nvidia's blob doesn't support rotation on dual head setups (you can either rotate no monitor or all monitors). Ok, I'll remove my old CRT, no big loss.

Second issue: if you keep a single monitor and rotate it, the blob stops vsyncing. Completely. My lovely desktop marred by lines and squares. The horror!

I tried both xrandr and the 'Option "Rotate" "CCW"' in xorg.conf. Same result: no vsync (and significantly faster 2d). Affects both Compiz and KWin (Metacity never had vsync so it doesn't count). I tried Nouveau and the situation is actually better there, the vsync failure is smoother - but it still occurs.

My question: is it possible to get vsync on a 9500GT when using a rotated monitor? Either Nvidia or Nouveau driver is fine with me - but if this cannot work, I'll swap in my Ati card.

FFS, Nvidia, your Windows and Mac OS X drivers vsync perfectly when rotating (and support mixed rotations in dual-head). Why did you drop the ball so hard on Linux?

[BlackStar]

Fake edit: "and significantly faster 2D". Of course, I meant "slower".

[Kano]

Maybe use nvnews board.

[BlackStar]

Maybe use nvnews board.

I just installed my Ati 4850 with the open-source drivers. Performance is visibly better when rotated, although some tearing remains.

I'll report this to the Radeon devs, instead.

[BlackStar]

Fake edit: https://bugs.freedesktop.org/show_bug.cgi?id=32789

[BlackStar]

For comparison's sake, I also tested with fglrx (the one that is bundled with Ubuntu 10.10, presumably 10.10). Performance is stellar in portrait mode (perfectly smooth, better than either nvidia or radeon), but vsync is, as always, broken (and the tearing more visible, due to the smoother scrolling).

[kazetsukai]

Think about what you're asking for... lol.

Vertical sync, when all of the v-timings are for the 1080 'vertical' pixels, and you're in portrait (1920 pixels) mode. The driver gets it right, but the applications have NO CLUE that you're rotated.

I'd imagine you'll get lots of weirdness from a rotated configuration, but answer me this- what is the behavior when the screen is rotated 180 degrees, rather than the 90 you're testing at?

[BlackStar]

Think about what you're asking for... lol.

Vertical sync, when all of the v-timings are for the 1080 'vertical' pixels, and you're in portrait (1920 pixels) mode. The driver gets it right, but the applications have NO CLUE that you're rotated.

I'd imagine you'll get lots of weirdness from a rotated configuration, but answer me this- what is the behavior when the screen is rotated 180 degrees, rather than the 90 you're testing at?

I just tried at 180 degrees and... it's still tearing.

Check the bug report above, it explains why it tears and explores a few possible solutions. This is a driver issue, not an application issue.

[BlackStar]

For the record, fglrx 11.2 with tearfree works flawlessly on rotated monitors. Finally, a proper v-synced desktop on Linux! Kudos, AMD.