Dual GPU issue with GTX295 on Linux

[yoyoz]

Hi,

I'm playing around with the demo version and I've some problems when trying to render with both GPUs activated.

I fisrt made a try with my default Xorg config and using the 2 GPUs gave me half of the performance of single GPU rendering. The "MultiGPU" option was set at "AFR" and I then thought that it was probably equivalent to SLI, so I disabled it.

I'm now runnnig without MultiGPU but I see no difference at all in terms of performance between single and dual GPU rendering. In both configs I also noticed that sometimes when moving the camera the screen was split in two parts and that one side would not update or update much slowly than the other.

I'm running Ubuntu 10.04 with Geforce drivers 260.19.29 and Cuda drivers 3.0.2. The NVidia control panels confirms that only one GPU is used for display and I look at the core temperatures to check which are in use during rendering.

Is there something I'm doing wrong?

Have a happy holiday season,
Yoyoz

[yoyoz]

I've also placed an order just before posting previous message.
Do you have an idea on when you'll be able to process it?

Thanks,
Yoyoz

[radiance]

Hey,

What kind of GPUs do you run ? Are you rendering with both chips on your GTX295 ?

Radiance

[yoyoz]

Hi,

I'm now having twice the performance when using both chips since I'm using beta instead of demo version, but I still have a black line in the middle although it tends to disappear when increasing the number of samples (see my post in "Work in progress"). This only happens when using both chips.

I've attached a clay render so you can see. As I was writing I made another test an got an even stranger result (screenshot attached too).

Thanks,
Yoyoz

[EDIT] may be you want to move this thread to another subforum as it's no more related to demo version