7800 Gt

Discussion in 'Mac Basics and Help' started by dsswarehouse, Oct 31, 2005.

  1. dsswarehouse macrumors newbie

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    Oct 15, 2005
    #1
    Do you guys think we will be able to install more then one of these in our systems; say in the x16 and the x8 PCIe slot
     
  2. G5Unit macrumors 68020

    G5Unit

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    #2
    Hey that would be cool. Check on nvidia.com and check if it is backwards compatable with X8 slots.
     
  3. RobHague macrumors 6502

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    Jul 8, 2005
    #3
    You can use more than one, you can have upto 4 graphics cards in the PowerMac Apple says.

    The first slot is 16x, then 8x and the last two are 4x (i think). The SLI boards out there run in 8x/8x so the second slot shouldnt be a bottle neck.

    Hopefully the 7800GT will retain its SLi compatibility and Apple will allow you to make use of it and support it. Not totally sure but it would be cool :D
     
  4. robbieduncan Moderator emeritus

    robbieduncan

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    #4
    On a PC you need an nVidia SLI chipsetted motherboard and the SLI connector bridge that came with the motherboard for this to work. As Apple don't appear to be shipping SLI bridges I don't think this is supported :(
     
  5. dsswarehouse thread starter macrumors newbie

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    Oct 15, 2005
    #5
    Well to overstanding sli is different then just two video cards; SLi combines the performance of the two cards into 1
     
  6. RobHague macrumors 6502

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    #6
    Hmm i thought that SLI boards were just optimized, i thought the real requirements of SLI was simply two high-speed PCIe slots. :( Shame, they are promoting Dual Cores and Quad Cores... surley Dual Graphics Cards wouldnt be out of the question for them to support.
     
  7. psycho bob macrumors 6502a

    psycho bob

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    #7
    As pointed out there is a difference between dual or more graphics cards and SLI. The G5 is aimed at the workstation market and for this SLI does not feature as no software utilises it. Gamers do like this feature but for the most part it is just hype, look at any test and you will see whilst SLI is faster the cost issue just blows it ot the water. Couple that with the fact that mac gaming on PPC is dead and none of the current games that are available with take advantage of such a feature and it would have been a pointless addition best left to Alien Ware and x86.

    The thought of two 7800Gt's powering twin 30in and twin 23in cinema display is a mouth watering prospect... imagine two Motion 2 projects on the go at the same time in HD lol :D
     
  8. madmax_2069 macrumors 6502a

    madmax_2069

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    #8
    SLI was first concived from 3Dfx they used it in there voodoo 2 video cards. All it was you put 2 voodoo 2 cards side by side and run the SLI connectou from one card to the other card. Ok say like each voodoo 2 card had 12mb vram and a single card would do only so many polygons a second, ok now combind those 2 same cards with the SLI cable from one to the other card now they are one card and combind vram of 24mb and double the polygons a second. since nvidia bought 3Dfx awile ago and took them awile to come out with a video card with SLI. the game's dont deside if SLI is used or not once you connect the 2 cards they will turn into one automaticly if there is a mac version out there. The cards driver desides that and if you turn it on all the games will use it. this is not like duel CPU's the game has to be enabled to use 2 cpu's
     
  9. RobHague macrumors 6502

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    #9
    I hope not :p or that 7800GT i want is gonna get dusty.
     
  10. madmax_2069 macrumors 6502a

    madmax_2069

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    #10
    I think gameing on a PPC Mac is far from dead. The PPC still has alot of life left in it. It's not going to be that fast of a transition from PPC to intel they arnt going to put a compleat stop on The PPC line cause to many people own PPC Macs just to stop bringing out software when the new Mactels come out not every one is going to junk there PPC mac just to get the First Rev Mactel
     
  11. psycho bob macrumors 6502a

    psycho bob

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    #11
    The point is software will be released for PPC but the gaming industry is different. Aspyr for example have already indicated that Call Of Duty 2 is unlikely to be developed yet this is a cracking game. The Havoc engine looks unlikely to see its way onto PPC so we can kiss good bye to games that use that which unfortunately rules out most of the ones that benefit from SLI technology ie; FPS. The argument that most people have PPC macs is immaterial when you look at the fact that only the top G5's can compete performance wise when running these games in the first place. When the transition to x86/x64 comes then we may very well see SLI but we won't see it in a G5. The G5 motherboard does not support SLI and as of the two GPU makers for mac only ATI make there own drivers and they don't even use SLI they use there own proprietry technology called Cross Fire it would come down to Apple again and they have no interest in it.

    The other big issue is the availability of these cards, as only the latest G5 dual cores support PCI-Express card makers won't exaclty be rushing cards out of the door for them given that within 12 months they will be obselete. Apple have stuck firmly with NVIDIA so the question remains will Apple offer retail kits like they did for the 6800 knowing that only the latest buyers can use them.
     
  12. madmax_2069 macrumors 6502a

    madmax_2069

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    #12
    only nvidia can use SLI "unless nvidia sold right's to ATI to use a form of SLI in there cards" cause they was the ones that bought 3Dfx and 3Dfx was the only ones that could use SLI or other video card manufacturers that used the voodoo 2 GPU's back in the day.

    If there is a Mac version of a nvidia video card that has the SLI ability than yea you can use SLI, but if there is no Mac version of the SLI card than no you cant unless you can flash the pc video card. SLI is purly based off the drivers for the card and the card's them self for SLI the only thing you hook to the logic board is the 2 cards in the slots next to each other, and to use
    SLI you have to have cards that support it then you connect the 2 cards together by a connector on the cards them self to each other. If mac's dont have the SLI supported cards then you cant use SLI.
     
  13. psycho bob macrumors 6502a

    psycho bob

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    Oct 25, 2003
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    #13
    Unfortunately SLI is not graphics card only dependant the motherboard does need to be compatible. In the case of the NVIDIA (true SLI by name) you need a nForce 4 based chipset and it is left to the manufacturer to supply the linking device to join the two GPU's as the spacing between the slots varies.

    Now other chipsets will no doubt become available but simply putting two SLI cards in even with capable drivers is unlikely to give you the results your after.

    SLI also introduces a very large CPU burden which is only made worthwhile when playing at very high resolutions with newer game engines like Havoc that make extensive use of shaders. Some games are not SLI capable at all such as M$ FS2004 so don't expect to see every 3D title benefit, infact only ones approved by NVIDIA utilise the technology there is no 'force SLI operation' mode in the drivers alas. Any resolution below 1600x1200 and the majority of top single cards can keep pace with SLI setups and at a vastly reduced price.

    So for now it is all pie in the sky, on the mac we don't have not the GPU's, the games (to really test SLI) or the motherboards in the computers to make it work so it is all here say.Until the performance gains are such that it cannot be ignored I see no reason why Apple will add these features especially as it does not effect their core market.
     
  14. dsswarehouse thread starter macrumors newbie

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    Oct 15, 2005
    #14
    Did anybody ever find out if it was possible to install more than one 7800 GT in the new G5's or if apple is going to have a retail board. I would really like to be able to install one of these cards in the x16 slot and another in the x8 slot. This would almost be like having the quadro 4500fx, I wonder if the power supply can support two 7800 GT's.
     

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