SLOW WHEN USING 2 GPUs on GTX 490 MAC PRO 2008

[joseetiger]

HI.

When using GTX 490 in my MAC Pro 2008(window 7 dedicated)

with Octane 3dmax 2011 plugin, it gets pretty slow when I render with two GPUs. It seems much slower

(GTX 490 have two seperate GPUs right?) than using one GPU.

Computer gets pretty slow and freaks out almost impossible to use, i have to force shut down my computer

I do lots of architectural rendering, maybe the scensize is too big. (around 300mb)

Do I need a helper card? Is the helper card will make it better?
Please let me know .


Thanks.

[roeland]

That is normal if you run Octane on the GPU that is driving your display. There is no scheduling on GPU's, so as long as the kernel is running on the GPU, it can't update the display, making the user interface lag behind. To avoid this issue, do not render on the card that has your display plugged in. Many people put an extra GPU in their computer (which can be a cheap one) to handle the display so they are able to use the computer while it is rendering.

--
Roeland

[joseetiger]

Thanks a lot Roland. I will buy a new helper card now.