Maximum PC

I am experiencing strange graphical issues in games with my new GTX 460 SLI setup. In every SLI-capable game, I experience random fluctuations in the bottom 1/3 of the screen. The image moves randomly in all directions and sometimes cuts off entirely to be replaced by a solid color. When I move the camera, it fixes itself or at least changes, but it is very annoying. I have tried forcing AFR, it didn't help. I removed all of my overclocks, it didn't help. I re-locked the 4th core, it didn't help. I tried VSync, it only got worse. They don't break 65C in FurMark. A quick search of Google yielded nothing. I have done stability testing on all of the likely culprits (Each GFX Card, CPU, RAM), no issues. I originally suspected the SLI bridge, since I have an MSI motherboard, but a new SLI bridge caused different a issue, horrible banding. I tried each graphics card on its own, and they are fine. I would test it without a bridge, but every time I remove the bridge, the SLI option in NCP vanishes with it. Could both SLI bridges be faulty? If so, Is there a way to use them without the bridge?

My system, for reference:

AMD Phenom II X3 740BE
MSI NF750-G55
ASUS ENGTX460 TOP 768MB SLI
6GB (2x2GB+2x1GB) Crucial DDR3-1066 @7-7-7/1.5v
500GB WD Cav Blk
Corsair 650TX
Sony DVD Burner
Antec 902
Win 7 Ultimate x64

No, don't move it...it includes prior overclocking! You are now left talking to the people that made your card dude. And possibly MSI that makes the board you put them in.

You're build (thus hopes) are astray. Help me Build/ BUY are right. It may not be a Video card issue, but rather the board. Did you ask for suggestions in HMB/B?

I doubt it is either of the cards, since the issues only occur when SLI is turned on, neither card individually has the issues.



My only problem with that is that it inevitably leads to the whole finger-pointing game. ASUS blames MSI, MSI blames ASUS, and nothing gets done.



Care to elaborate on that? It went together fine, aside from the graphics bugs.



I didn't, graphics bugs led me to think graphics forum, thus, here I am. I was mainly hoping for insight as to how to enable SLI without an SLI bridge, and to find out about any well-known issues, whether with 460 SLI specifically, something interfering with it, or with SLI in general, that would cause this sort of issue.

If I could enable SLI sans bridge, that will help me clarify the issues. If it works, It's the bridge. If it doesn't, then I can proceed to calling for RMA's and such.

Can you find a place to order a new bridge? Possibly a call to the card mfr would net you a new bridge. It would certainly be cheaper for them to try that than making you rma both cards.

My motherboard originally came with one. After the initial malfunctions, I called MSI and got them to send out another. I suspected a bridge issue as well, since I experience different problems with each bridge. I'll try ASUS, thanks.

EDIT: ASUS was of no help, but MSI is shipping out another bridge. Should be here Wednesday or Thursday. In the meantime, any other ideas, or other ways to test it without the bridge?

A couple of basic questions come to mind as you haven't addressed them yet.

Have you checked out your power supply. While Corsair's TX series is very good and has a very good rep, it is still possible to get a bad one that be giving some flaky voltages on on the 12v rail. According to this article by Anand Tech you should be drawing about 500-525ish watts (that's total sys load) with those cards in SLI. Do you have access to another PSU? Push come to shove you may try removing it to a local shop that can properly load test it (I'm paranoid so I would want to make sure they could in fact load the unit and didn't just use a DVM to check the voltage).

It is important to remember that the load will fluctuate depending on where you are in your game or current endeavor. This variation can cause fluctuations in the voltage avail at the various rails. To much variation and things can get screwy. You could try to monitor this your self with some success with a program like Everest to monitor the voltage real time. You may try to do it with a DVM hooked up and watching it while you loaded up the system. But you really need be able to see what is happening as it loads and unloads to make sure the voltage regulators are doing what they should.

Have you updated the BIOS recently? As in everything was fine once upon a time, but now it's not. If not have you checked for the latest BIOS? You may read the basic descriptions of each to see if any address similar problems.

Have you confirmed that you have the latest chipset drivers for your specific motherboard.

Have you tried completely uninstalling all nVidia software removing the cards and starting over with the drivers and software.Be sure to follow recommended procedures/use nVidia removal sftwr/rmvl tools, or something like Driver Sweeper.

I don't know about nVidia software/hardware, but part of ATI's recommended procedure is to remove their folders after uninstalling and then going to the device manager and in properties for the cards clicking on uninstall for each card. Just before doing the restart I even empty the recycle bin so Windows can't go there to reload anything. Note; Windows generic drivers are good enough to get you up and running on the restart with one card till you get their software installed.

If all your software (drv's and BIOS) is up to date, both cards run fine, your PSU is good to go, and you have replaced your bridge but the problem is still there, I would say the problem has to be with the mobo itself.

I don't have another PSU to test, but the integrated digital meter (I know, not always accurate, but my board doesn't have test points) shows the +12v as being at or above 12v at max load with furmark, prime95, or crysis.



I'm using Everest. The +12v stays between 12.14v and 12.1v.



There is a new version, but all it seems to do is disable Active Phase Switching (a power-saving feature) during Overclocking. I will try it, though.



I reinstalled Windows when I installed the new components. I was using 32-bit and wanted to use 64 to take advasntage of all 6GB. When I did, I got the latest 750a drivers from nVidia.



I was experiencing the same issues before reinstalling Windows, when I used my components while backups were going.



I formatted the partition. Would you like me to try uninstalling all of it again?



Thanks, that's where I'll look next, if the new bridge doesn't fix it.

EDIT: I updated the BIOS, no change.

Final Edit: Got the new SLI bridge in, it looks different, darker, and the MSI logo on it is different. I put it in and voila, problem solved. Thanks for your help, everyone!