PCE 2.0 slot GPU card placement on 3-way sli mobo

Mugen-G

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Oct 27, 2009
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Hello!

quick question, If i have a mobo with 3 PCE 2.0 slots and i wan't to run 2 Nvidia cards, 1 as a dedicated physx
card.
Besides the main card(3D) being in the first slot, can the physx card be ran, say in the 3rd slot instead of the 2nd?

The mobo in question supports X16 X16 X0 OR X16 X8 X8 3-way sli

Now why not try it instead of asking? well i don't have said mobo yet but are considering it instead of a 2-way sli mobo. the simple reason being convenience, 2 cards on a 2 slot mobo leaves me with no PCI slots free while the 3 slot mobo does, but it does only with the PCI slot being next to the middle PCE 2.0 slot. because both cards are double slot sized and they would probably kill each other with heat, especially the gtx 260 with an after market cooler and 2 top 80mm fans would have no breathing room if i use the slot 1 & 2 config...

I realize SLI has nothing to do with any of this...
ahh...yeah that about sums it up... :kaola:
 

Mongox

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Your motherboard manual will give you the answer. I've never heard of x16 x16 x0 but maybe if I saw it in print. But you didn't list the brand/model of your board.

You can get the manual at the mfg site - don't rely on anything from a sales site. Read the manual fully including the section it will have on installing GPUs.

I've never heard of a PCIe x16 slot being next to another without another slot between them.

Post the info on the motherboard - we can't divine the answer simply by throwing dice!

 

Mugen-G

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Well i just tried to download the pdf manual but i can't seem to get a connection to the msi download page, don't know what thats all about...

Anyway the Mobo is the MSI NF980-G65, the cards are the palit GTX 260 and a EVGA 8800GTX gateway edition (looks similar to the BFG 8800GTX) once you look at the MOBO you will see what i mean about the space between the PCE 2.0 ports, it says X16 X16 X0 OR X16 X8 X8 on the MSI site.
 

Mongox

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I'm convinced that there's only ONE WebServer on the island of Taiwan - it's an old IBM-AT sitting in the backroom of a waterfront bar. Nothing else can explain why the country that makes such great motherboards and other computer products can't seem to run a website that runs as fast as the slowest site in Australia.

I got the manual. And btw, I'm not really compentent on high-end GPU issues or choices. Heck, I use the built-in GPU on my board and even reduce its RAM usage to 128MB!

Regardless, the manual seems to be saying with the 16, 16, 0 thing that if you install two identical GPUs, the 3rd slot is disabled. That is, if you take advantage of the 16,16, you lose one slot. If you run the 2nd GPU in 8 mode, the 3rd slot will take another 8 card. Doesn't actually say that tho! But being able to run 16 and 16 is I believe still pretty nifty, so it's the way to go from what I read. I think you'd only want the 3rd slot if adding two less powerful GPUs to your primary. There's a utility to run to activate the slots, the pairing, the speed, etc...

And yes, if you put in two matched high-end GPUs it will likely obscure one normal PCI slot - but many PCI cards are designed for this - I just got a PCI Wireless N card that is cut off on the back to avoid the space used by a big GPU. And you'll still have one full-length PCI slot if you only plan on using 2 GPUs.

I believe almost all paired GPUs are designed to go in adjoining PCIe 16/8 slots, with a PCIe 1 or other slot between them. Never seen a setup with 3 slots between. So the issue of cooling isn't an issue, since they're designed for this configuration. Will they tend to get hot, sure, but that's why you have the extra fans. I don't think it's a problem - or not one they aren't designed for.

Hope this helps and you'll still want to study that manual cover-to-cover before buying.