[SOLVED] SLI option not appearing in Nvidia Control Panel

Solution
One card is seated in a x16 PCI slot and the other a x4, does this matter?

i haven't follow SLI tech for years but if the requirement does not change yes that is the problem. unlike CF, SLI need the PCI-E slot to be x8 regardless of the version of PCI-E on the board (for example PCI-E 3.0 x4 bandwidth is the same as PCI-E 2.0 x8 bandwidth but SLI will not work on PCI-E 3.0 x4 but will work on PCI-E x8 slot).

i look at your motherboard spec it seems the board did not support SLI (the second x16 only run at x4). the requirement for SLI is a bit strict. even if the second slot did wired for x8 configuration you still need board with SLI certification. it was BIOS check to enable SLI function. if the motherboard are not...
One card is seated in a x16 PCI slot and the other a x4, does this matter?

i haven't follow SLI tech for years but if the requirement does not change yes that is the problem. unlike CF, SLI need the PCI-E slot to be x8 regardless of the version of PCI-E on the board (for example PCI-E 3.0 x4 bandwidth is the same as PCI-E 2.0 x8 bandwidth but SLI will not work on PCI-E 3.0 x4 but will work on PCI-E x8 slot).

i look at your motherboard spec it seems the board did not support SLI (the second x16 only run at x4). the requirement for SLI is a bit strict. even if the second slot did wired for x8 configuration you still need board with SLI certification. it was BIOS check to enable SLI function. if the motherboard are not certified you might be able to use BIOS hack to work around it but the x8 slot is mandatory to have.
 
Solution