jerky 3d animation?

[gabrielefx]

Hi Erik,

I haven't connected my gpus in SLI because I use my Titan system for render: iray, octane, etc. There is no bridge connection, it's not recommended.
Fortunately Titans are faster than K20x...and can be overclocked.

Ventuz runs smooth on all the other gpus I own. I think that on my Titan system there are bios issues, I hope that Asus will check the Z9 motherboard with 4 Titans.
I agree that Ventuz needs pro gpu drivers. I have had Quadro boards, drivers are not perfect.

I don't think that Ventuz uses special low level instructions for Kepler chips, it's directx based except you will add a realtime raytracing node.
Then Ventuz runs exactly like Crysis or Lumion.

The jerky issue is a timing problem, in every animation cycle I see a drop frame, the interval between every drop doesn't change in time, is equal.

Regards

[gabrielefx]

Jitter confirmed!

just now I installed the PLE on another system with 4 GTX580 3GB.

This system is totally different from the Titan one.

A simple axis + cube + mover in loop at 360° in full screen at 2560x1440 has jitter (jerky animation every cycle, drop frames, or name it as you want)

Then the issue doesn't come from the GTX Titan or 580 but from four gpu systems or the latest Nvidia GeForce drivers.

I remember that Nvidia added some timing tweaks in the drivers. I haven't touched anything in the Nvidia control panel.


Regards

[gabrielefx]

I did another test:

I started on these two systems (4xTitans and 4x580) two animations: same scene

every 6,1 seconds on both systems I recorded jittering.

This is strange...6,1 seconds on both systems...(different hardware, same Samsung monitors, same scene)

now I will try to change the monitor....

[gabrielefx]

found the cause!

it comes from the Samsung SM27A850 monitors!

I connected one old Apple Cinema Display with a 1680x1050 resolution....and the animation had no drop frames...

[Christian Krix Schmidt]

Glad you found the cause for that.

[ErikB]

This is good information, thank you for doing the tests and posting. I didn't think of the screens as the culprits.

BTW, while we do not use specific instruction sets from Kepler, we might well use some of the PRO-specific features such as synch hooks. (both on AMD and Nvidia) So even if we don't seem like we go low-level in the renderer, it is very possible that timing and such could be very different in game drivers and can have an impact on Ventuz performance.

-E

[gabrielefx]

In fact is very strange that the monitor (both twin monitors) cause a sync drop.
In a simple animation (the simplest possible but also in the most complex) I see that it lacks some frames, cyclic drop frames.
Connecting another monitor all the animations were smooth...incredible but true.

I see that in the monitor config there is an option: fast, medium, normal response...but no way
Probably my monitors are not ok for videogames because both Titan and GTX580 cards generates drop frame on this particular Samsung model.

Tomorrow I will test my new iiyama capacitive display.

Regards.