PCIe connectors 3 and 4 only have 1 x 8 PCIe lanes. This
creates a problem for cards that require 2 x 8 lanes. Not all cards
are supported in connectors 3 and 4.
- Verify the cards in I/O connector 3 and 4 are not cards supported
only in I/O expansion connectors 1 and 2. The following link to the
Service Guide describes cards supported only in I/O expansion connector
1 and 2.
- If the card is in the correctly supported connector, replace the
card.