GTX590 issues

[teffo]

I just ran the benchmak scene with both GPU's and it works well.

Now the major dealbreaker is when importing a DAZ3D scene that takes 800-900MB Vram. It renders fine on ONE GPU (available GPU VRAM~1200MB). So that's fine.
Now, selecting other GPU (#2) in preferences, available VRAM NOW reports 800MB, and Octane reports 1 GPU failed.

So the question, is why does available memory drop so much, if at all, when selecting the second GPU?

George

[PhillieDFilms]

Are both cards GTX 590s? I had a similar issue with dropping RAM when running two diff vid cards. Roeland from Octane gave me the answer. Here is the post.

http://www.refractivesoftware.com/forum ... 23&t=18129

[teffo]

Thanks for the reply.

I have a single 590.
Simply enabling both reduces memory significantly. I wonder if this would not be an issue with separate cards like you have.

I own a 480 as well, so I may just try to use both today and verify if this problem is due to twin GPU cards only.

George

[teffo]

Ok update -

GTX 480 + GTX 590 work well when you only run GPU1 of the 590 and GPU of 480. Memory left is ~1300MB - that's ok
Now if I select 590 BOTH GPU,480 turned off, then memory ~600MB - VERY BAD!

So it appears if you want optimal performance, you need two SEPARATE video cards,not a multiGPU card like 590.

So in that regards, I put the 480 and 590 up on EBAY and bought 2x GTX 580 3GB for 800 bucks on EBAY. Well lesson learned.

George

[teffo]

Disabled multi GPU in driver and all works as it should.

Selecting all GPU's report correct video RAM. Ok so now Iown a few more GPU's - so these wil be used for the other 2X6core 5690 XEON SR-2 system.
So one system has 2X 590's and the other has 2X 580 (3GB), so I'm fine with that.

Just a big headache, but I'm glad I resolved the issue.
Still need to buy another Octane license for the other system.

I also upgraded my home solar panels so the load will be evened out. Big money spent , but I take rendering seriously.

George

[gbambo]

One reason memory might be reduced when switching between two identical cards, or when selecting both, is that one card is the system card, servicing Windows and other apps. That card has less than all of its memory available to Octane therefore. It looks to me on my system as if Windows and Chrome, etc. can consume up to 400mb of vram. One card is essentially unused in a pair. Thus Octane sees the fully spec'd memory available. The other has a fraction of that available. If you select both, Octane downgrades both to the lower available memory status between the two.

At least this is my understanding from numerous discussions posted elsewhere.