These boards support SLI:

   2-Way SLI

• P55 Micro (121-LF-E652-KR)
• P55 (132-LF-E655-KR)
• P55 FTW (132-LF-E657-KR)

   3-Way SLI

• P55 FTW 200 (141-LF-E658-KR)
• P55 Classified 200 (160-LF-E659-KR)

This board does not:

• P55 LE (123-LF-E653-KR)

All of the P55 Series boards support Crossfire, however longer-length Crossfire bridges/cables may be necessary.  These bridges/cables are not included with the motherboards, only SLI bridges are.  Contact your graphics card manufacturer to see if any are available.