Nvidia certifies SLI parts with added logo stamps
 

The SLI Ready logo means the component in question was sent to Nvidia, and it got some poor intern who annoyed the wrong person to test them all together. Lots of cross testing, but in the end, if you go out and buy the logo'd pieces, they should play well together. That is a good thing.

http://www.theinquirer.net/?article=19595