PCIe Splitter

[dionysiusmarquis]

Hi there,

anyone ever tried PCIe splitters in conjunction with Nvidia GTX Cards (780/780ti/titan)? The splitters are running at 1x and i'm not sure if theres additional bandwidth loss. I can live with 1x PCIe speed but 1/2-1/4 1x would be a little to much loss i think.

It's very common with ATIs for Bitcoin mining, but does it work for GPU rendering like Octane as well?

thank you

[Octopot]

You must mean PCIe risers 1x to 16x adapters? I'm sure it will work, but you will need those risers with molex power modded to them to provide the extra juice.

Here is a render rig this guy did with his bitcoin setup with 6x gtx 750's (5 of the cards are 1x to 16x pcie extenders) http://www.geeks3d.com/20140502/geforce ... x-gtx-750/

1x will drop your rendering speed I think, I rememeber noticing a test render speed drop at 4x (16x & 8x pcie slots are barely noticeable)

[dionysiusmarquis]

No, I'm actually talking of splitters: http://amfeltec.com/products/flexible-x ... -splitter/

But does the bandwidth not just affect the amount of time needed to feed the vram?

[Octopot]

oooh, hmm maybe this item looks interesting http://amfeltec.com/products/flexible-x ... -oriented/ , could not find any price but looks like a netstor'ish concept there.

*a bitcoin website mentions those risers to be in the "...hundreds dollars range..."*

[dionysiusmarquis]

Yeah its too expensive (https://bitcointalk.org/index.php?topic ... #msg214445).

When I understand what happens to the bandwidth with such splitter I would go for something like this: http://www.ebay.com/itm/PCI-E-Express-1 ... 43c60df93a

[glimpse]

"1x will drop your rendering speed I think, I rememeber noticing a test render speed drop at 4x (16x & 8x pcie slots are barely noticeable)"
no true, rendering speed is going to be the same is it would be conecting to 16x - the only difference will be in loading time.

I haven't seen abnyone here talking about active splitters (maybe talking but not actually using), so I really doubt anyone will give You exaact answer =) I'd advice to try.

In theory I don't see a reason for them not to be working, but I believe the speed should drop - if it's not something like a PLX chip in the..they should penalise speed of data movement (but that's only logic, based air..)

Hei why not taking a card with let's say 6-7 1x pci conectos to have such monster? are You looking to have a bigger beast?

[dionysiusmarquis]

Yes I'm planning to build a breakout box with 4 GPUs per 1x PCIe which have their own Power supply and cooling System. If everything works fine you could multiply your PCIe connections by 4 (24 GPUs for a 6x PCIe Motherboard). This Thread https://devtalk.nvidia.com/default/topi ... -it-works/ made some good points about the feasibility.

Man that would be so awesome.

[slepy8]

An electricity bill would be even more awesome

[dionysiusmarquis]

An electricity bill would be even more awesome

Who cares? THAT WOULD BE 24 FRICKIN' GPUS IN ONE RIG!!! Hahahahaahah.

Nah, I'll start with 4 anyway, but thats some nice picture.

[mate]

Here's another crazy idea: is it possible to run an octane rendernode on a (eg windows or linux) HPC setup?