Perfect multi-gpu scalability.

[grabiller]

.
1x GTX480 = 4.40 Msamples/sec
2x GTX480 = 8.60 Msamples/sec
4x GTX480 = 16.67 Msamples/sec
8x GTX480 = 32.20 Msamples/sec

2x GTX480 = (8.60/4.40)/2 = 0.97727
4x GTX480 = (16.67/4.40)/4 = 0.94715
8x GTX480 = (32.20/4.40)/8 = 0.91477

It's really perfect !!
It's more than expected !!
I am happy.

Hello,

Out of curiosity, how do you manage to use 8x GTX480 at the same time ?

Do you have several extension boxes, or a specific mobo, etc.. What's your setup ?

On my Asus Rampage III Extreme I can't use 4x GTX480 ( the fourth is simply not detected.. ) so I'm using 3x for now, but I'd like to add more and I'm not sure how to do that. I've seen the GPU-X but it seems you can't chain those.

Thanks in advance for advises and informations on this.

Cheers,
Guy.

[radiance]

He's got some photos of his special case+mb+PSU somewhere on the forums, can't remember where though...
maybe use the search function on the forum.

Radiance

[grabiller]

He's got some photos of his special case+mb+PSU somewhere on the forums, can't remember where though...
maybe use the search function on the forum.

Radiance

Thanks Radiance, found it :
http://www.tyan.com/product_SKU_spec.as ... =600000150

That said, I've just discovered those :
http://www.amax.com/CS_Tesla20-Series.asp

Seems pretty interresting too ( very scalable solution ).

I'm trying to find the right solution for an upcoming feature length 3d animation movie I'll have to handle.

On the hardware side, there seems to be several good options.

On the software side, I'll wait for Octane to handle displacement, volumic light/rendering ( I guess MLT will help on this ), object motion blur and material animation ( especialy with area light/material emitter ). RIB support will be a must once available, for animation, especialy if we can specify all Octane materials parameters and other settings from RIB files so we can manage materials databases outside from Octane, and use scripting from 3d animation packages ( using Softimage|XSI here ).

Crossing fingers..

Cheers,
Guy.

[El Burritoh]

Yes, Radiance and Face, you guys have created one amazing piece of software. I am excited to see where this leads!

[EricNV]

I've seen the GPU-X but it seems you can't chain those.

No, but you can add a GPU-Xpander PCIe adapter for every open PCIe slot you have in your PC. For instance, on the Asus Rampage III Extreme motherboard, you could attach a Cubix x8 or x1 PCIe adapter to each open slot (approximately $350 price increase going from x1 to the x8 version, x16 will be a bit steeper) and run 6 x GTX 480 cards off of that ASUS motherboard.
EricNV

[grabiller]

I've seen the GPU-X but it seems you can't chain those.

No, but you can add a GPU-Xpander PCIe adapter for every open PCIe slot you have in your PC. For instance, on the Asus Rampage III Extreme motherboard, you could attach a Cubix x8 or x1 PCIe adapter to each open slot (approximately $350 price increase going from x1 to the x8 version, x16 will be a bit steeper) and run 6 x GTX 480 cards off of that ASUS motherboard.
EricNV

Hello Eric,

Thanks for your answer and informations.

Currently, I have 4x WC GTX480 occupying the 4 PCIe slots. The issue I have is that the 4th card on the PCIe slot #4 is not detected for some reason. I'm well aware this mobo doesn't support 4way SLI, but I'm not using SLI as Octane require it to be disabled. I'm then puzzled why the 4th card on PCIe slot #4 is not detected. I've checked the ASUS forum but no one seems to have this problem. I'm then not sure what would happen with a Cubix PCIe adapter plugged on this slot #4.

Are you aware of an existing setup with this ASUS Rampage III Extreme mobo with 4x GTX480 ( or Cubix ) occupying the 4 slots that is actualy running as expected, with the 4x GTX480 ( or Cubix ) well detected ?

I also have a question for you, regarding the Cubix itself : could it accept 4x GTX480 if each one only takes 1 slot wide ? ( watercooled GTX480 only occupy 1 slot, that's why I'm asking ).

Cheers,
Guy.

[EricNV]

I've checked the ASUS forum but no one seems to have this problem. I'm then not sure what would happen with a Cubix PCIe adapter plugged on this slot #4.

Is that slot actually receiving power from the motherboard? Have you tried installing a different PCIe card as a test?

Are you aware of an existing setup with this ASUS Rampage III Extreme mobo with 4x GTX480 ( or Cubix ) occupying the 4 slots that is actualy running as expected, with the 4x GTX480 ( or Cubix ) well detected ?

No, we haven't run across an ASUS Rampage III yet, although we are very familiar with the ASUS product lines since we've used them extensively in other product lines such as LaserBlade.

I also have a question for you, regarding the Cubix itself : could it accept 4x GTX480 if each one only takes 1 slot wide ? ( watercooled GTX480 only occupy 1 slot, that's why I'm asking ).

The only problem I can see is the power draw. GPU-Xpander Pro 2 has a 750w power supply, and the GTX 480 can draw as much as 282(?)W per card (somebody correct me if I'm way off please). However, GPU-Xpander is available with a 4-slot option for single-width cards.
EricNV

[grabiller]

Hello,

I got the 4x GTX 480 working now.. How ? I'm actualy not sure and this is still a mystery to me..

Check the Asus forum where I posted there about my issue :

http://vip.asus.com/forum/view.aspx?id= ... uage=en-us

Everything is working fine now, and Octane surely benefits from the 4 cards together. That's impressive.

Cheers,
Guy.

[radiance]

Hello,

I got the 4x GTX 480 working now.. How ? I'm actualy not sure and this is still a mystery to me..

Check the Asus forum where I posted there about my issue :

http://vip.asus.com/forum/view.aspx?id= ... uage=en-us

Everything is working fine now, and Octane surely benefits from the 4 cards together. That's impressive.

Cheers,
Guy.

remember that once you reach the vsync of 60FPS or the tonemapping limit of a small render resolution you won't get linear speedup anymore with 2.2.
you need to render at higher resolutions and with complex scenes (with pathtracing) to really see the nearly linear speedup...

Radiance

[grabiller]

I understand,

my rendering targets are HD, Full HD and 2K ( 1:85 ).

I can already see the near linear speedup at these resolutions, both in path tracing and direct lighting modes.

That's really great.

I'll be able to start some tests for our feature length 3d animation projects, to decide if we take the risk to go with Octane or not. The production wont start before January 2011. This will also depend on the features available in Octane at that time. We may be well the first production company to take this risk, afaik. We can discuss this privately if you like, it would be helpfull to us to have a more precise idea of the roadmap, for us to have a better visibility on what we can expect at that time.

Cheers,
Guy.