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No performance different in Single card v.s SLI ? WHY?

592 Views 15 Replies 10 Participants Last post by  3000gt
I've been using dual 7900GTX 512MB in SLI for a while now but only recently notice this after install some program to monitor frame rates while gaming... that my frame rates per second is the same while in single mode nor in SLI mode.

First, I switched between single mode and SLI in the 3D setting from NVIDIA Control Panel... noticed no different in performance

Then, I took off a card physically... then switched the card to see if they are both working properly ... then SLI but PFS on all 3 scenarios are the same I got 64 fps in World of Warcraft... no increase in performance whatsoever.

And yes... I know how to enable SLI in the expert board... if not it wont even confirm that I'm in SLI mode. I already checked on that.

Can someone tell me whats happening here?? I'd really appreciate.. Thx in advance
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well with a single 7900GTX could dominate anything but with that CPU it could be holding you back.. also make sure your sli bridge is seated correctly
Where can i find Vsync at???
Yes I do have the latest drivers from Nvidia website... my CPU is currently running at 2.85 Ghz so I dont think it bottlenecks....

Theres one thing I wanna bring up tho... I'm running 3Dmark06 right now with a single card and noticed a drop in performance... But, Why not in World of Warcraft??
Weird, maybe Wow doesn't support SLI?
edit: paradox beated me to it!
<try Battlefield series, thry all are SLI optimized
im not suprised, some games can even be a little worse with sli. most games will see a 20-40 percent increase though.
I can confirm that WoW does support SLI... There are thousands of gamers on my server using SLI.... as WoW is the biggest online game right now...

Originally Posted by [email protected]
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Weird, maybe Wow doesn't support SLI?
edit: paradox beated me to it!
<try Battlefield series, thry all are SLI optimized

hmm, maybe you can help me... when i froce max settings i get a weird kinda lag when i rotate.. but i get 75fps pinned..
^ video
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I'm fairly certain it is the fact that your monitor is too small to notice the difference. SLI for those sort of high end cards really requires a larger monitor, with at least 1920x1200 resolution. Otherwise it is overkill since a single one of those cards can handle 1280x1024 with absolute ease.
with TWO gtx, you only get 60or so fps in wow? with my one card, i got 75 almost all the time, but not in if when everyone was there...maybe its a bad driver or something? i just wish i had my sli done...the wife wont let me get that second card, even tho its 100 bucks less now that when i bought first one!!
It's definitely his Vsync then.
It's a bug or crappy coding in WoW where dual core CPUs have their framerates capped at ~64 FPS. They fixed it in the 1.12 patch, but then pulled it from the servers b/c it was conflicting with some code. Should be patched again soon, or possibly in this last patch (2.01). Link is to the forum thread addressing the issue.


For now(assuming they haven't fixed it yet), run WoW and go into your task manager and set the affinity to only 1 core.

2 x PCI Express x 16 (*SLI mode : x8 , x8 *Default Single VGA mode : x16, x1)

in sli its only taking x8 from each one and in single it's taking all x16 from one
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