Multi GPU question

[geo_n]

Your motherboard doesn't even have to support sli ( mine doesn't and it works beautifully).
Just be sure to have several PCI express slots with 16x or 8x speed and your good to go.
(and if octane has some trouble to see your second gpu the only setting to check out is the PhysX one in the nvidia control panel).

happy rendering

Thank you. Time to do some renderings.

[CoCo]

I made another test at work (still on the benchmark scene):

#1 test : only one gpu (main), Geforce GTX 275
=> 4.66 Megasamples/sec

#2 test : only one gpu (second), Geforce 9800 GTX+
=> 2.25 Megasamples/sec

#3 test : both GPU
=> 2.18 Megasamples/sec

so the slowest card will in fact give worse results
the multi gpu mode is in fact powerful when using the same cards.. ?

[Amplitude]

coco be sure to turn pathtracing on in the render kernel. By default the benchmark scene is in directlighting mode and shouldn't.

[CoCo]

You mean the Multi GPU mode is only effective using Pathtracing ?
I'll try when i've a minute

[Amplitude]

no, but at least your results will be comparable to others... or expected results.

You have to know you're not the first user to report this, I think there are two threads already in these forums speaking about that.
I experienced it myself (both GPU stucked at 60% max instead of 90%) but a reboot take care of it and I haven't had it since...

[scarecrow2k6]

@Coco- Check this thread:
http://www.refractivesoftware.com/forum ... =25&t=1934

I think you are having a similar problem like one mentioned there. I have a Gtx 470 and a Gtx 285. Msi Afterburner tool shows both the card is working while rendering in Multi GPU mode but I'm actually getting the performance of the GTX 285. I checked the status of the cards with GPU-Z tool, it says only my 470 is cuda enabled and 285 is not. You can try out similar test and see what you get.

@People with multi GPU working- can someone please post a screenshot of their Octane Render Device Manager. Thanks.

[Amplitude]

just tried the benchmark scene with multi GPU to take a screenshot for you and I have the same problem as you guys....
FYI I just had DWG Viewer (autocad) and Archicad launched for the whole day... very strange as if some part of the card's power was reserved or something...
Usually after a reboot , the full performance is back.

[Amplitude]

just to put a picture on the problem:

that is a serious issue. Any insight on this Radiance?
(granted that after a reboot , the performance is back to full blast?)

[mlody47]

yeah im not rendering multi gpu for now too. I got no slowdowns but definetly not much increase.

Like it would say iits multi gpu but rendering on one.

[radiance]

Hi guys,

make sure SLI is turned off.
also, non-fermi cards are currently giving issue like this, we're trying to optimize/make a work around.
we'll improve this with beta 2.3

Radiance