sli with plx chip

[gary0001]

hallo.
anyone having experience with a 3 way sli gpu configuration with a z97 socket with plx chip??
is it nesessary to upgrade my socket to have a well running triple sli configuration??
my mobo is MSI Z97 XPower AC.

 

[dudmont]

I have a z87 xpower(I like it a lot, great board). I have a pair of 780tis. Three way sli setups don't scale well. Doesn't matter what system you have it in. 2 way sli scales pretty good(maybe 90% or so), but the third just doesn't seem to give you that much improvement. I have a 4790k and the pair of cards and an O/C cpu run well. I think a google search can give you some specifics, in terms of what to expect for scaling purposes, but it's just not as effective after the first sli card.

 

[Spectre694]

you don't really lose any performance by using the PLX chip for SLI even in four way. However, dudmont is right SLI/crossfire don't really scale great after two cards for most games.

 

[gary0001]

besides the percentage of the improvement the third card would give...(in a heavy game lets say).
i want to know if the plx chip can manage to run the three cards as one.. smoothly

 

[Spectre694]

besides the percentage of the improvement the third card would give...(in a heavy game lets say).
i want to know if the plx chip can manage to run the three cards as one.. smoothly

Yes your PLX will cause no problems

For performance in general roughly (been a while but they should still be close enough)
one card =100%
two = 130-140%
three 160-180%
four = 190-200%

 

[gary0001]

ok so the plx chip is capable in a Z97 socket with some restriction in the PCI-E lanes to run the triple sli configuration well?

 

[dudmont]

ok so the plx chip is capable in a Z97 socket with some restriction in the PCI-E lanes to run the triple sli configuration well?

absolutely. It would run 4 cards, if you could keep it cooled and afford the cards. PLX is basically a repeater chip, sending the same data to all the cards, it's up to the sli bridge to allow the sli control part to function. it causes a slight lag(imperceptible).
That board has a middle slot(just like my z87 xpower), that bypasses the plx chip, if you're only running one card, but otherwise, multiple cards need to be in the plx slots.

 

[gary0001]

ok dudmont you are looking my issue from the right angle
right, the slight lag(imperceptible) that the plx chip will cause, in what way will i understand it, how will it influence or affect the whole configuration mobo gpus and monitor.
i want to know practically... (meaning in a game, lets say crysis3 from the moment i move the character to fight with the keyboard and mouse will the lag be between my movement and the depiction in the monitor??
hope you can understand me...

 

[Spectre694]

ok dudmont you are looking my issue from the right angle
right, the slight lag(imperceptible) that the plx chip will cause, in what way will i understand it, how will it influence or affect the whole configuration mobo gpus and monitor.
i want to know practically... (meaning in a game, lets say crysis3 from the moment i move the character to fight with the keyboard and mouse will the lag be between my movement and the depiction in the monitor??
hope you can understand me...

none zero zilch nata nothing (a milisecond or two maybe). That is what the word imperceptible means. Your monitor will have way more to do with any input lag than a SLI with PLX setup will. You might could have some microstutter but that is inherent in SLI/xfire and has nothing to do with PLX chips.

 

[gary0001]

thank you gyus everything is clearer now!!!