9800gtx or 8800gt/gtx for x8 pci-e

Hi all

Just got a few questions

Just recently got a new system but was not aware that the board was only 8x pci-e when in ran in sli

the board is an asus p5n-e sli

I had my eye on a few cards in cluding 9800gtx and a few of the 8800 series

I have recently read on a few forums and apparantly the 9800gtx will not run in sli mode at x8 speed pci-e and that for these cards to run in sli it requires a sli motherboard that both have 16x slots

If this is the case for the 9800 cards is it the same for 8800 cards (if i buy 2 of the 8800's will they run in pci-e?) or do they also require 2 x 16x pci-s slots to run?

also which would be the best card for me to get as im now pretty limited for sli lol

Im not realy bothered about it that much but just want the best preformance from system so would I be better going for 1 9800gtx+ or would I better better getting 2 x 8800gt/gtx/gts and running them in sli if this is at all possible?

cheers ppl

10 answers Last reply
More about 9800gtx 8800gt
  1. A pair of 8800GT's will decimate a single 9800GTX+ and even put a hurting on a GTX 280.

    You will have no problems SLIng any current GF8/9 GT 200 series card on your Mb.
    It has the 2x PCIe 1.1 16x slots required for SLI.
    With a single card installed, it will use all available 16 lanes for it.
    When you install a second card, it will split the 16 lanes between the two cards effectively halving the bandwidth per card.
    It may not be the best motherboard for a high end SLI setup but it will work.
  2. cheers outlw6669

    Is it not true then that the 9800 requires 2x pci-e x16 slots 2 run?

    thanks for quick reply dude

  3. No, that would be incorrect.
    A single graphics card will only require a single physical PCIe 16x slot.

    Due to the nature of PCIe, it is possible to have a physical 16x PCIe slot with less than 16 PCIe lanes connected.
    This is what happens when you install 2 GPU's in a SLI setup on your motherboard.
    As the northbridge only has 16 lanes dedicated to graphics, 8 of them are shut off from the first connector and activated on the second.

    You can easialy tell the diffrence between PCIe 16x and lower slots bye the size.

    As long as the PCIe slot is able to fit a 16x card, you can run any PCIe device in it.
    That is to say, if you had a PCIe 4x card, you would also be able to run it in an 8x or 16x slot.
    Of course, in your case you are only concerned about PCIe 16x GPU's.
    The rule of thumb with PCIe is if it fits, it should work.
  4. thanks again outlw6669

    just to confirm then (sorry for being hassel im quite new to this and dont wanna spend a foryune on 2 9800 gtx's if there not going to run on my momtherboard)

    If i buy 2 9800gtx's and sli them they will run?? but not obvisously at x16 only at x8 speed.

    if this is the case would 2 of the 8800gtx's or any 2 of the 8 series run or preform better than x9800gtx's in sli mode?

    ps this is what got me worries about it lol


    if you read the bottom of the page it says about this card requiring x2 16 speed pci-e slots to run

    cheers in advance guys
  5. For the amount you would spend on a single 9800GTX or 9800GTX+, you can get a equal to better performing HD 4850. Check Newegg.com, they run as low as $150 after MIR. 8800 GTSs seemed to be a little over-priced for their performance. The cheapest run at the same price as the HD 4850 and are seriously outclassed. A cheap 8800GT for $120 would be a better deal. It might only be worth it to go SLI if you had 2 x16 lanes. Since you don't, performance will suffer noticeably. Then again, if you can find reviews of 2 8800GTs in SLI and they show that performance doesn't decrease that much, go that route and SLI them.

    Oh, and if you're willing to drop the money for SLI'd 8800GTs and GTSs, you should take a look at the HD 4870, which might complete closely with 8800 GTs in SLI given your PCIe situation.
  6. as far as i am aware gcards are a locked architecture where as motherboards can very 16x:16x / 16x-8x:8x , you will not really loose performance in 8x:8x mode especially running the 9 series cards , and if you want sli go for it , later on down the track upgrade the mobo as 16x:16x series become cheaper pending on your cpu class ,

    what people are confused is that some games use sli whilst others don't but when used performance is hugely boosted , go for a card on or over the 512mb range and more games are utilising sli (another plus for the end user)

    sli will continue to grow as room now on motherboards are becoming available with the reduction of extinct ports
  7. cheers coolheat sounds good to me :) its says here though on the link at the bottom of page that x2 9 series cards in sli require a board with 2x x16 pci-e slots ?? mine is an asus p5n-e sli 1 pci-e slot @ x16 or 2pci-e slots @ x8 speed ??

    http://www.overclockers.co.uk/show [...] =GX-074-BG

    Will this work?? or will I only be able to run x1 9 series card or x1 8 series card

    cheers guys
  8. No problem.
    Yes, you can run 2x 9800GTX+ in SLI just fine on your motherboard.
    IDK what that disclaimer is all about as it should work just fine.

    There are only 3 SLI setups that will outperform 9800GTX+ SLI.
    Those 3 would be a 9800GX2 SLI, GTX 260 SLI or GTX 280 SLI setup.
    A pair of 8800GTX's would perform similarly to a 9800GTX SLI setup but would loose in the majority of games.
    Where they may perform better would be at ultra high resolutions with AA and AF turned up.

    If you decide to stick with 9800GTX+ SLI over your other options, I would recommend saving some cash on the cards.
    The minor overclock offered bye BFG is not worth the £50 premium you would pay for a pair of These.
    Overclocking your GPU is a simple matter and I am certain you can get more performance for free than what you have to pay to get with the BFG card.
  9. thanks outlaw much appreciated thats been a real big help :) just saved me some cash :)

    what would you recommend then for a sli setup for best preformance/cash on my board? 2 x 8800gts/gtx or 2 x 9800gtx
  10. For the best Price/Performance I would recommend a pair of These 8800GT's.
    It will save you £70 and still give you damn good performance.
    In this case, the overclocked version is well worth the $$.
    An extra £3 from the cheapest gets you 1/6 higher core speed (700Mhz vs 600Mhz) an extra 50Mhz (100Mhz DDR) on the RAM and an upgraded cooler.

    Although not an exact match in the benchmarks, see the multi GPU benchmarks from Anandtech's 48X0 review.
    It will give you a general overview of the performance differences between SLI 9800GTX+ and stock SLI 8800GT.
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