Back in late August, Nvidia decided to give Intel and its partners a chance to implement SLI on X58 boards. Nvidia offered two options, hardware SLI support with its Nforce 200 chip, or software support for a nominal fee. Additionally, some sources suggested that Nvidia charges mainboard manufacturers around $5 per unit for its SLI licenses.
It has been known for several months now that most X58 boards support both Nvidia SLI and ATi CrossFire technologies. According to a recent report, however, one Gigabyte user over at the Guru3D Forums has reported that the GA-EX58-DS4 he purchased does not support SLI but only supports CrossFire.
According to an article from DVHardware written back in October, only the Gigabyte GA-EX58-UD5P, GA-EX58-Extreme , and GA-EX58-UD5P were confirmed to receive X58 SLI licensing.
In general, Nvidia commands motherboard makers to use SLI approval keys, called "cookies," in the BIOS to pass certification. Moreover, these "cookies" ultimately enable SLI support in the company's Nvidia Control Panel software, which is installed with its GeForce drivers. On the other hand, ATi's CrossFire does not require an approval key, which is why most boards are already CrossFire supported from the beginning.
Furthermore, Nvidia admitted back in August that some users will likely hack the BIOS of non-certified X58 boards and add "cookies," thus enabling SLI without the company's certification, but this hasn't happened so far.