Discussion in 'Videocards - NVIDIA GeForce' started by GErnstSmit, Jul 8, 2011.

  1. GErnstSmit

    GErnstSmit New Member

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    Nvidia 560 Ti
    Hi there,

    I am planning to build a gaming PC and have done a lot of research on hardware to find out what is the best value for money. I want great performace but don't want to waste money on small improvements or simply to be able to say I have the best gear on the market.

    So with that in mind I'm looking at the following setup:

    Motherboard: Asus Sabertooth with P67-B3 Chipset and Mil spec components
    CPU: Intel Sandybridge i7-2600K 3.4GHz Quad Core, with overclocking
    RAM: 8GB (2 Pair 2GB) Kingston Hyper-X T1 DDR3 1866MHz,CL9,support XMP, Tall Heatsink
    PSU: Coolermaster Silent power Pro Gold 1000W, 80Plus Gold, Modular Cabling
    Case: Coolermaster HAF-X Nvidia Edition
    CPU Cooler: Zalman CNPS11X Extreme
    GPU: 2 x Asus ENGTX560 Ti DCii, 1GB 256bit DDR5, 384 cuda cores @ 1.8GHz

    My question concerns the motherboard and SLi setup.

    The Asus Sabertooth uses 1 PCIe in 16x mode, but when 2 cards are inserted it runs the 2 PCIe slots in 8x mode. Does this lack in PCIe bandwith cause a bottleneck and will it slow down the 560 Ti cards running in SLi?

    I could go for the Asus P8P67 WS Revolution board wich supports 16x + 16x + 8x + 8x SLi, but that board costs 30% more. Will I get a 20 to 30% FPS increase running the cards in 16x + 16x vs. running them in 8x + 8x or will there be a small and unnoticable performance increase only?

    I'm not looking at going for a 3-way or 4-way SLi setup so the extra slots will never be used.

    Your opinions on the setup and on the PCIe bandwidth issue wil be appreciated greatly!

    Thank you,
    Ernst Smit
  2. Pill Monster

    Pill Monster Banned

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    7950 Vapor-X 1100/1500
    You prob won't notice the difference tbh....afaik gfx cards still can't saturate PCI-e 16x .....what settings/res do you use normally?

    If you're on a tight budget then why aren't you looking at a single card setup?

    Btw if you want any decent help then get a mod to change the title of your thread or else just start a new's a bit vague. :)
    Last edited: Jul 8, 2011
  3. crap daddy

    crap daddy Master Guru

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    The difference between 2 x8 and 2 x16 is minimal. No need to worry.
  4. pooley

    pooley Member Guru

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    xfx r9 fury
    Quoted for truth..

  5. TruMutton_200Hz

    TruMutton_200Hz Ancient Guru

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    Iris Xe

    EDIT: No, the Nvidia NF200 MCP of the Asus P8P67 WS Revolution (or of any other motherboard, for that matter) does not magically add any bandwidth. All it does is distribute, between multiple PCIe x16 graphics cards, the total of available bandwidth - by adding more PCIe lanes between it and the PCIe x16 slots to which it can connect. So no, a x16 link through the NF200 is not at all faster than a native x8 link that runs straight from the Sandy Bridge CPU to a PCIe x16 graphics card. However, since the NF200 adds latency, a x8 link through the NF200 is nevertheless slower than a x16 link through the NF200.

    On a side note though, the Asus Maximus IV Extreme uses PLX switch technology which makes it able to completely bypass the NF200 (and therefore, to bypass the latency which the NF200 adds) so that the NF200 on it will not (at least, not if you're following the recommendation in the product manual of the motherboard) be used at all until more than just two PCIe x16 graphics cards are installed on it.

    So basically, current Sandy Bridge on socket 1155 with P67 / Z68 has 16 PCIe lanes built directly into the CPU, which can be used to either run a single PCIe x16 graphics card in native x16 mode, or be split up into two separate x8 links to run two PCIe x16 graphics cards rather than only one. If you'd need more than two PCIe x16 graphics cards on this, that's when an NF200 would start to make sense.
    Last edited: Jul 9, 2011

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