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Re: Nvidia FX 9800
Posted: Thu Feb 11, 2010 6:20 pm
by radiance
Hey,
Octane will support using multiple GPU's soon (in a few weeks),
without using or needing SLI.
So a double card like a GTX295 could be good.
you could start using it currently, use the 2nd card (sub-card of the dual card in one) for rendering,
and the first card for display, then you get a responsive display while rendering with octane...
then later on, you can use both when octane supports it.
Radiance
Re: Nvidia FX 9800
Posted: Sat Mar 06, 2010 5:03 am
by juan
THATS SO GREAT!
i have a question, how is it going to handle the Vram ? i mean is it goingo to create the scene twice (in each card´s memory) or is it gong to be distributed in both?
if not , could be this possible? (hope so
)
thanks
Re: Nvidia FX 9800
Posted: Sat Mar 06, 2010 6:30 am
by YoonKyung
juan wrote:THATS SO GREAT!
i have a question, how is it going to handle the Vram ? i mean is it goingo to create the scene twice (in each card´s memory) or is it gong to be distributed in both?
if not , could be this possible? (hope so
)
thanks
I hope so too, but as far as I know, each GPU must have same scene and data.
If not, data traffics between GPUs will make performance seriously down,
since band width of PCIe(2GB/sec(r/w)) is much lower than that of VRAM(90GB/sec).
Code: Select all
c:\> bandwidthTest.exe
Running on......
device 0:GeForce GTX 295
Quick Mode
Host to Device Bandwidth for Pageable memory
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 4908.7
Quick Mode
Device to Host Bandwidth for Pageable memory
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 4860.2
Quick Mode
Device to Device Bandwidth
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 93794.1
&&&& Test PASSED
Press ENTER to exit...
Re: Nvidia FX 9800
Posted: Sat Mar 06, 2010 6:57 am
by MadMinstrel
As I understand it, both the cards need only the scene data. It would be nice to split the render target between them, which can get pretty large on a 12MP image.
Re: Nvidia FX 9800
Posted: Sat Mar 06, 2010 7:02 am
by YoonKyung
MadMinstrel wrote:As I understand it, both the cards need only the scene data. It would be nice to split the render target between them, which can get pretty large on a 12MP image.
Yes, each GPU don't have to keep entire render target, I agree with you.
Re: Nvidia FX 9800
Posted: Mon Mar 15, 2010 5:46 pm
by reberts2
So SLI will not be needed, utilized or valuable in an existing or future Octane setup?
Thanks.
Re: Nvidia FX 9800
Posted: Mon Mar 15, 2010 5:47 pm
by radiance
reberts2 wrote:So SLI will not be needed, utilized or valuable in an existing or future Octane setup?
Thanks.
no, cuda does not use SLI.
SLI is only for directX and OpenGL games/apps.
Cuda uses the GPUs as separate processors much like multiple CPU cores.
So it can function with a mix of different GPUs and no SLI is needed.
Radiance