Harwarezone tested the GA-K8XP-9 mobo which is based on NVIDIA's nForce4 Ultra chipset:

Gigabyte has provided us with both of their nForce4 Ultra based motherboards for our shootout, the GA-K8NXP-9 and the GA-K8N Ultra-9. The former is the higher end of the two and more fleshed out in terms of features. The GA-K8NXP-9 also features Gigabyte's Dual Power System (D.P.S.) and Memory Intelligent Booster 2 (M.I.B.2). While D.P.S is a physical module consisting of an additional 3-phase power circuit to help stabilize voltage regulation, M.I.B.2 is an algorithm to detect and boost memory performance. Categorized under Gigabyte's 9-Sigma series of motherboards, the GA-K8NXP-9 is one board that is packed with features and peripherals.



Link: HardwareZone