So here is the deal, I just got my new computer that is running dual 8600Gt cards. Both cards are recognized on my system. However, supposedly to enable SLI all I am supposed to do is go into the nVidia control panel and enable SLI. However, there isn't an option in the nVidia Control Panel to enable SLI. The cards are bridged.

It seems this is a common problem from some of the forums I've read, but I can't seem to find any solutions to the problem.

Here is my configuration:
-AMD Athlon™ X2 5200+ Dual-Core CPU w/ HyperTransport Technology
-Asus M2N-SLI NVIDIA nForce 560 SLI Chipset w/7.1 Sound, Gb LAN, S-ATA Raid, IEEE 1394, USB 2.0, Dual PCI-E MB
-2X nVidia GeForce 8600GT 1GB
-Windows XP SP2
-Latest version of drivers (v 169.21)

Any ideas on how I can enable SLI, if the option is not on the control panel? Or suggestions on what I need to do to get it to show up on the control panel, so I can enable it?

It is a driver issue with the latest drivers. Rumor has it that you need to downgrade the driver to 162.22 (or older) to enable the option for SLI. Try it and let me know how it works for you.



This post has been edited by Martyr2: 2 May, 2008 - 09:37 AM

Thanks for the tip, Martyr2. Installed version 162.65, that got the option available, so I can now enable it.

However, it has brought a new issue. While SLI is enabled all I get is a black screen after it reboots.

The only way I can currently run is with one card disabled.

Sighs.. why can't things just work the way they are supposed to?!?

Any suggestions?

What is your Power supply wattage and your computer monitor type?

If you are running two of these cards you are going to be drawing a bit of juice, so you should have over a 500 watt PSU and from what I understand some monitors especially from gateway LCDs have problems understanding the DVI output when SLI is enabled.

So make sure your mobo is getting all the power it can for these cards and that if you have a gateway LCD using DVI you could try connecting it to the VGA using a DVI to VGA connector.

Last case scenario fix is trying this driver which is said to allow the SLI as well as people reporting it has cleared black screens...

NGO NVDIA Optimized Driver v1.913

Hope one of the solutions work for you.

Power supply is "650 Watt -- Coolermaster Extreme Power Supply SLI Ready" and monitor is Acer LCD 22".

So I don't think that is the issue. I will give the driver a try and see what happens.

Tried the driver, however it didn't work. Wasn't able to install it. Said it wasn't able to find a compatible set of installed drivers.

Will check with tech support on Monday.

Wow, you really are having a tough time with this. Typically it isn't this hard. You usually put on the bridge, install the drivers, enable SLI and off you go. Most people with the 8600 cards that have problems have it fixed after putting in the old drivers. Strange.

Sorry I couldn't help more with this.

No worries. I appreciate any and all help.

Thanks for yours.

Another thing could be defective bridge.

Negatory ghost rider

You will need high amperage on the 12v rails and a 24 pin powersupply I cant remember the specifics you may want to also try running it with out the bridge there were some drivers that were supposed to eliminate that but I cant remember if they went live or not. The first SLI cards required the bridge and you had to have 2 of the exact same card. supposidly now they can be of diffrent manufactures as long as they have the same on card memory. The SLI system I built had a OCZ modstream powersupply that had 24 amps on the 12v rail. powering a DFI lanparty motherboard. I have since sold that system but it was sweet when i ran it. The Socalled 650 Watt Coolermaster powersupply i had only had 12 amps on the 12

Also Make sure that you have all the power connectors hooked up there may be one on each video card or a couple IDE looking Molly connectors on the motherboard specifically for the videocards. when it reboots will it run windows just fine but bluescreen on any 3D game?

Thorian, the problem was not when running games, it was after enabling SLI and rebooting the computer. It would go to a black screen during the boot process, right after the Windows logo showed up.

Todays cards still require the bridge for proper operation. The bridge allows for data transfer between cards without having to go across the FSB. Although they will work without the bridge, it is best to use it, from my understanding.

Anyhow, I actually resolved the problem last night. I pulled both cards and again tested them individually, as was the case the first time, they both worked just fine. However, this time I decided to swap which slot they were in, ie. moved card in top slot to bottom and vice-a-versa.

Rebooted computer and everything is working just fine now. SLI is enabled and both cards show as running at 8x.

Thanks for everyones help!