Adding third GPU

[canoedad]

I currently have two EVGA GeForce GTS 250 1GB DDR3 256-bit 756MHz PCI-E 2.0 DirectX 10 Video Card - 01G-P3-1155-TR. I want to add a third but cannot locate one. The only ones I can locate are either 738 clock speed or 771. Which one would be better, or does it not matter?

[EEVIAC]

What's the make/model of the motherboard your adding the card to?

I'd imagine that if the card you want to add is not going to be used in a SLI/cross fire setup it wouldn't matter, and the higher 771 MHz card would be better..

[canoedad]

The MB is an EVGA 790I ultra ands it will be in sli with the other two

[EEVIAC]

hate to pop your balloon, but there are only two cards supported by your board for a three-way set up: NVIDIA GeForce 8800 Ultra &  NVIDIA GeForce 8800 GTX.

Given the two cards you already have, if you added another card is would not be able to utilize the 3-way setup capability of the board. 

[canoedad]

hate to pop your balloon, but there are only two cards supported by your board for a three-way set up: NVIDIA GeForce 8800 Ultra &  NVIDIA GeForce 8800 GTX.

Given the two cards you already have, if you added another card is would not be able to utilize the 3-way setup capability of the board. 
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Sorry bubble not popped, this is an answer from EVGA>



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Question (2/14/2010 1:23:59 PM): I currently have two EVGA GeForce GTS 250 1GB DDR3 256-bit 756MHz PCI-E 2.0 DirectX 10 Video Card - 01G-P3-1155-TR. I want to add a third but cannot locate one. The only ones I can locate are either 738 clock speed or 771. Which one would be better, or does it not matter?
Answered By Dave B (2/14/2010 1:30:31 PM): Hello,
I would advise in this case, the 771mhz edition, and to install it in the primary slot, you can also run the 738, they would all be compatible as long as they are 250's and have the same memory volume.
 

[t_blake07]

I would contact EVGA again, and ask if your board only supports the 8800's in 3 way SLI. They aren't gonna answer a question you haven't asked about. All customer service support is this way. They would let you put 10 cards in there if it supported it. But would they bother telling you that only one card was compatible with this setup? Probably not. Unless you specifically asked about it.

[patio]

EVGA although a fine outfit...would be more than happy to sell you another Vid card...
However it appears he did not check that MBoards specs.

[canoedad]

I would contact EVGA again, and ask if your board only supports the 8800's in 3 way SLI. They aren't gonna answer a question you haven't asked about. All customer service support is this way. They would let you put 10 cards in there if it supported it. But would they bother telling you that only one card was compatible with this setup? Probably not. Unless you specifically asked about it.

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Thank you for contacting the EVGA Customer Service Team.
My name is Stephan Kern and I will be answering your question today. Please do not reply to this email, submit any follow up questions here
Question (02/16/2010 11:45:48 AM): Will my mother board support 3 gts 250 cards? 
Answered By Stephan K (02/17/2010 2:15:24 AM): Steven,

Yes your motherboard should be able to support 3 gts 250 cards.

Thank you,
EVGA

[EEVIAC]

The question you asked Tech. support was far too vague...

You should have asked if the board supports three of the GTS 250 cards in a 3 WAY SLI setup?    You may be able to fit three cards into the board, but that doesn't mean 3 way SLI will be enabled..


If you have so much faith in EVGA tech. support why are you posting here on this question?

[BC_Programmer]

As its name implies, EVGA nForce 790i Ultra SLI motherboard is based on the latest high-end chipset from nVidia for the Intel platform. What is new on nForce 790i compared to its predecessor, 780i, is the support for DDR3 memories and PCI Express 2.0 support generated by the chipset itself – nForce 780i was in fact an nForce 680i with an additional nForce 200 bridge chip making the conversion between PCI Express 1.0 and PCI Express 2.0. Both chipsets support 3-way SLI mode, which allows three GeForce 8800 GTX’s or three GeForce 8800 Ultras to be connected together, and Quad SLI, allowing two GeForce 9800 GX2’s to be connected together and enjoining four GPU’s, as each GX2 is powered by two GPUs. Two of its three PCI Express x16 slots are PCI Express 2.0 and this motherboard has also two Firewire ports, optical SPDIF output and more.

I think that is pretty clear...

[t_blake07]

I still have the box for my 780i, and here is what it says:

NVIDIA SLI Technology: Two SLI-Ready GeForce based Graphics Cards. (same card)
                                       
                                           Three GeForce 8800 GTX or 8800 Ultra Graphics Cards.


I would have to say that 3 way SLI is not capable with three GTS 250's. Two way, yes. Three way, no.

[EEVIAC]

I still have the box for my 780i, and here is what it says:

NVIDIA SLI Technology: Two SLI-Ready GeForce based Graphics Cards. (same card)

Just out of curiosity, have you looked around for, or tried any of the nVIDIA Forceware drivers?   I know that there is support for 2-way without the card being exactly the same.  Only requirement, I think, is that the GPUs need to be from the same family...  Forceware v81.85 may be up your ally if your looking for a cheaper replacement at some point..

There may be support for three way setup also, if the cards are not exactly the same, given the same circumstances..

[t_blake07]

Just out of curiosity, have you looked around for, or tried any of the nVIDIA Forceware drivers?   I know that there is support for 2-way without the card being exactly the same.  Only requirement, I think, is that the GPUs need to be from the same family...  Forceware v81.85 may be up your ally if your looking for a cheaper replacement at some point..

There may be support for three way setup also, if the cards are not exactly the same, given the same circumstances..

Actually, I don't have the motherboard anymore. I just kept the box and manuals for some reason.

But you're right, if we're on the same page. The cards have to both be 8800's, 9800's, etc. As long as the memory is the same they should work. Even if one card is EVGA and the other card is ASUS.

I was also thinking that there could be updated drivers and/or BIOS to support 3 way with other cards by now.