When upgrading to a socket 939 motherboard without SLI support, the Asus A8N-E (nForce 4 Ultra) is a popular choice among users, noted for its reliability and performance. Many users report positive experiences after using the board for extended periods, typically around two months, without encountering issues. Other recommended brands include Abit and DFI, with the DFI Lanparty series receiving particular praise for its quality. Reviews from sites like NewEgg are often used as a basis for purchasing decisions, highlighting the importance of user feedback in selecting a motherboard.