GTX 460 SLI problems/questions

calmstateofmind

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So a few months ago I built a new gaming system, here's the specs:

-EVGA GeForce GTX 460 1GB (Fermi) x2 SLI
-Intel Core i5-750 OCed @ 3.8GHz
-Corsair Nova 32GB SSD
-Samsung 2TB HDD
-WD 750GB HDD
-WD 1TB external HDD
-EVGA P55 SLI motherboard
-8GB CORSAIR DOMINATOR DDR3 RAM @ 1333MHz
-Rosewill Xtreme Series 850W PSU


I just recently bought the 2nd 460 and have ran benchmarks with both cards enabled and with only one. Between the two I'm only seeing a small difference in frame rate. I'm wondering if there was a way for me to verify that both cards are in fact being used? I have EVGA Precision and on the charts it shows activity and I see both cards listed in Nvidia Control Panel, but I still don't see it reflected in the frame rate. I'm running the Lost Planet 2 benchmark.

Is there something I'm missing?


P.S. My first card is in a x16 2.0 and the other is in a x4. Would there be a noticeable difference in perform between the two because of that? Does that effect the SLI in any way?

Thanks in advance.
 

skolpo

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Sep 20, 2009
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Some basic questions: Is SLI enabled in nVidia Control Panel? Are you using an SLI bridge? Are both cards powered correctly with two 6-pin PCIe power connectors for each card? Download GPU-Z to check if your SLI is enabled.
 

calmstateofmind

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Yes, I'm using an SLI bridge. Yes, the power connectors are 100% secure and have 2 6-pins in them. I have looked at GPU-Z and it shows both cards, but does that mean that the SLI is in fact working or just that both cards are being recognized? Where in the Nvidia Control Panel do I have the choice to enable SLI? Is that SOP for SLI?
 

skolpo

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In nvidia control panel, under 3D Settings, there should be a menu that says "Set SLI and PhysX configuration." Make sure you have the latest drivers. In GPU-Z, at the very bottom, right above "Computing", it says NVIDIA SLI. If your SLI is working, it will say "Enabled (2 GPUs)."
 

calmstateofmind

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I opened GPU-Z and under Nvidia SLI it says disabled!!!

I have the bridge connected, the card is getting recognized by my device manager, GPU-Z, EVGA Precision and HWMonitor so I know everything is connected correctly. When I opened Nvidia Control Panel I didn't see anywhere of it mentioning SLI, only "CUDA GPUs" and then it check marks both cards automatically. Please help!
 

calmstateofmind

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Yes, I downloaded the driver utility thing from Nvidia's site. But, I just cracked open the case and changed PCI slots and it works now! The cards are literally right next to each other though, is that going to cause a heating issue?
 

calmstateofmind

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Actually, another problem has occurred. I've managed to get the option of the SLI to be enabled in the Control Panel, but every time that I enable it, my screen blacks out (as if it were making changes) but then my entire computer freezes and I have to hard reset. Any ideas are much appreciated.
 

calmstateofmind

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I just did a clean install of the drivers, along with the control panel and everything else and then reset my pc. I turned it back on, opened the control panel and selected sli again. Hit apply. It sat there for a few seconds saying it was loading and then it went blank, my mouse pops back up (but the rest of the screen is blank) and it stays frozen. The entire computer.

 

skolpo

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ebay has plenty and they're relatively cheap. But let's not conclude that it's the bridge's fault just yet. Have you tried running benchmarks with the new card only? This will test whether if the new card might be faulty or not. You can even try to swap the cards and see if SLI works that way instead. Also, try what mousemonkey say and run the computer with only one stick of RAM, or at least try reseating them to check if that fixes the problem. If that doesn't change anything, then you should start trying older drivers.
 

calmstateofmind

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No I haven't but plan on doing so in the morning. I'll also try to single stick of RAM. I think the problem is just with drivers. If it were with the card itself, I don't think it would be as influential with the rest of the system as it is. I'm going to try older drivers real quick to see if that's the issue. If not, more to come in the morning.
 
I just found this picture showing the bridge and does look like a ribbon rather than a hard PCB.
evga_p55-sli_kit.jpg

Is this the same as yours?