External Graphics Cards PC

[Anamorphic]

Hi

Is anyone using external graphics cards with Octane on a PC ?

I am looking into whether it is a good idea to have a PCI enclosure case like the one below;

http://www.scan.co.uk/products/netstor- ... -and-cable

Does anyone have any experience of these ? Do they run as quick if they were internal ?

Thanks

N

[glimpse]

hi, Anamorphic.

There are plenty of Guys who are using external GPUs on this forum & those run great. Computer sees PCIe cards as if they were physically inside of computer.

Performance (rendering speed) will stay the same & the only difference is going to be upload time, tat will be influenced by connection speed - lane account, PCIe gen =)

On the other side 80W is not so much.. at best You can power up is 750 (Ti). Recently ASUS release interesting SKU based on 750 - STRIX, having not 1 or 2GB (like most of 750s), but 4GB =) - the only problem here, even if You can power this thing, You might end up having to tear Your nice box into pieces..as physically it would be hard to put that card inside..

so what's the solution? well, to buy a bigger box, with more power & be able to house bigger cards, or..choose this route ( I should get my hands on it in the end of this month & I'll share my experience if You're someone will be interested =)

Keep in mind that connection speed for this kit is even lower & power brick is limited =) but You can buy it without it & choose regular (ATX) or SFX power supply (recently those come up to 600W) - so there are options.

P.S. if You want box for Your new parts - there's a user in the forum with milling machine =) maybe he could help You to make custom piece so You can fit Your chosen parts into nice package =)

[itou31]

Hi glimpse,
I would be interested in this solution also, that seem cheaper than a full box. I have a spare 580GTX and a 400W ATX powersupply.
I'm waiting for your test.

[itou31]

Finally I think to buy the 4x Amfeltec splitter. Do you have some feedback ? it's for windows platform.

[itou31]

I have request some information from amfeltec, and it's better to take the 4x. Note that each 16x adapter has only one 1x lane but independant, so if you have 4 GPU, they all work at 1x full (but spec 1.0 --> 250MB/s bandwidth). For the 1x version splitter to 3 adapter, each apdater share the bandwidth but it's spec 2.0 (500MB/s). So, the 4x is better if you have at least 2 GPU.
I have ordered one to test (wait at least 3 weeks...)

[itou31]

Hi,

Just received the 4x splitter Amfeltec.
And still waiting for a 4x PCI-E riser (ribbon) to get access to the 3 PCI-E slot between my titans watercooled.
As I have a spare PC to test, here are some benchmark (base on OctaneBench) :

bench

Test on a titan black

[glimpse]

Nice! =) Thanks for sharing!

a bit curious though - rendering speed should not be influenced by running on slower interface =)

are You going to run those extra cards on air? (mentioned You have a watercooled build)

[itou31]

Yes, I think that I will let them on air first.
My watercooled setup is not enough to handle 2 more titans.
And for performance, i think that the 1x spec 1.1 is not enough (I see here a drop of 3 to 4 %).
Otoy specify at leat 4x to see no performance degradation.

[itou31]

Just received the riser... chinese one but works.

add quickly the two titan black to the PC to test ... (need to make an external box to protect these GPU)

Set overclock these black a bit and result a 109 score each one on OctaneBench.
And score a 517 with all 5 titans (3 normal + 2 black).
As expected, the air cooler one get hot up to 75°C.
For the system i7 [email protected], at boot, power consumption at primary power cord is about 400W.
In windows standby : 220W (if I disable in device manager the 2 titan black, it goes up to 260W ! I though that if I disable GPU, the power should go down, but not)
When start a render, power goes up to 1460W (CPU + 5GPU) and then stablilize at about 1250W (at primary power).

[itou31]

To complete my tests :
Just received another riser 4x. I test to extend the previous one : 35cm length in total and its works.
I just see a splitter 1x to 4 adapter 1x with cable USB3 (extended to 1m) for about 60€. You could then plug 1x adapter to 16x riser for 10€ each (USB 3 cable). So that mean you could extend to 2m ! I don't know if it works but the price is cheaper (100€) than amfeltec (1x to 3 adapter 16x) 200€. and the lenght is not a problem anymore !
I have order one riser 1x (USB3) to test.