Significant lagging with Sony HMZ-T2

[Sven]

Hi,

we were using Vizard 3.0 with a NVIS SX60 HMD and an Intersense 900 Tracker. This worked ok. Recently the NVIS broke, and we are at the moment looking into replacing it with a Sony HMZ-T2. However, we are experiencing significant lagging during head-turns. Is this caused by the graphics card? With the NVIS, we used a nVidia Quadro FX3700. As the Sony needs HDMI input, we are at the moment using a low-budget Radeon HD 6450.
Does anybody know if the lagging can be reduced with a better graphics card? Or is this caused by th Sony HMD and cannot be remedied?

[Jeff]

It sounds like it could be a limitation of the graphics card. Did you run the same script on the system with the quadro card? What is the framerate when Vizard is running (Press F4)? Have you tested with a simple script? Just load a simple model like gallery.ive with your tracker and display settings and see if the lag is there.

[Sven]

Yes, it is the exact same script as before. In fact, the whole hardware setup is the same - we only exchanged the quadro card with the radeon (and the most recent drivers for it) and the nvis with the sony.
I checked the framerate, it is always at 59-60 Hz, both with my script and the simple script you suggested. The image is never stuttering, it simply lags behind. I guess I'll try a better card then.

[Sven]

OK, tried it again with a new, more powerful card (ATI Radeon HD 7850). Still get the same lagging, though. Anyone have any ideas why?

[Jeff]

When you run the Quadro card with the Sony HMD does it work fine?

[mspusch]

from what you describe, it sound like the lag has to do with the tracking used.

i believe the IS900 is typically integrated directly with the nVis, how did you integrate this with your Sony HMD?
are there any differences?

did you try the setup with just an inertial tracker (like an Intersense 4)?

just a thought ...

[Sven]

Hi,

unfortunately, I can't use the Quadro card with the Sony, as it only has DVI-Outputs and no HDMI. I tried several DVI2HDMI Adapters, but none of them worked properly.
By now, I'm fairly sure that the problem is with the Sony HMD - if I combine the tracker with a small portable monitor instead of the HMD, the lagging vanishes. Googling about the HMZ-T2 and lagging also brings up several hits - apparently, this problem did improve a lot since the T1, but it is still there. Maybe we should wait for the T3, or at least tell our test subjects to avoid fast head movements...

[Markus]

We use a Qualisys tracking system in combination with a k4000 quadro card and the HMZ-T2. I have not tested the latency of the components jet. But so far i have the same impression, that the HMZ creates a latency of about 200 ms .....