We just got contacted by a friend of the site that inform us that the crew over at Ukrainian xDev website managed to reverse engineer the SLI verification procedure and now SLI works everywhere. In case you didn’t knew, nVidia charges motherboard vendors five dollars [US$5] per motherboard if the motherboard is to support GeForce SLI. In terms of Quadro SLI, the company charges more and it only certifies complete systems, rather than motherboards. We suspect that this is what keeps an iron fist on the Quadro board market, where nVidia captured over 90% of the market.

But the main issue with SLI is the fact that there aren’t many AMD motherboards on the market supporting SLI, and renaming nForce 780a into 980a SLI was well? a closely followed pattern by nVidia in the past 24 months, with more rebrands than new ASICs.

Well, not anymore. According to xDev website, they found two ways how to activate SLI on ALL multi-GPU supporting motherboards, regardless of the chipset in place [but you have to have a minimum of two closed or open-ended PCIe slots fitting the graphics cards].

They’ve tried and tested SLI on 16 motherboards, from the oldest P965 and P35 to new AMD 790X chipsets and it worked every time. From graphics cards side, the team had pairings of nVidia GeForce 6600LE, 6800Ultra, 7900GS, 8800GTX, 9800GT, 9800GTX, GTX260-192, GTX260-216 and GTX285. The guys checked to see if their method works on 32-bit versions of Windows XP, Vista & 7 and 64-bit versions of Vista and Windows 7. In each and every case, the SLI worked.

Now, there are two ways to achieve this hack. From one side, you can use modified drivers but that method requires a hacking and tweaking each and every time you install a new driver. But there is a second method that allows you to install newer drivers – by replacing HAL [Hardware Abstraction Layer] and cheating the operating system about the motherboard chipset you have. Even though operating systems work in general, this experiment might result in a non-bootable system. In that case, do a simple reboot or perhaps even have your installation crash.

You can read the whole guide in this following link: xDev: Activating SLI on all motherboards, detailed HOW-TO.
In the end, the credit goes to the author and programmer of modification SveetSnelda, and anatolymik for modifying the HAL.dll.

Update September 29, 2009 13:55 GMT – We received word from Mr. Ken Brown, PR Manager in nVidia Corporation, as nVidia’s official position on the software run-around:

"NVIDIA licenses SLI technology to all major motherboard manufactures for use with certain SLI compatible chipsets.  NVIDIA tests theses logo?d and licensed boards for compatibility and ensures that our multi-GPU technology works flawlessly with current and future applications and driver releases.
 
Any hack can result in system instability, so NVIDIA continues to recommend that our customers use SLI-certified motherboards for the best experience."

There you have it folks, given that software run-around [especially HAL.dll one] may render Windows useless, it might pay to go for nVidia-certified product. Then again, if you want SLI on an AMD platform and can’t get nForce 980a…