Nvidia's chipset line for Intel motherboards started with the Pentium 4. There may have been relationship issues between the two companies that prevented Nvidia

Nvidia's chipset line for Intel motherboards started with the Pentium 4. There may have been relationship issues between the two companies that prevented Nvidia from entering the Intel chipset market sooner using a derivative of their Xbox chipset, but none of that has anything to do with what ended the nForce chipsets for Intel.