4-Plus-1 is officially Nvidia’s new name for the Tegra 3′s fifth core as announced today via their blog. NVIDIA’s design approach is unique in the industry in that it uses TSMC’s 40nm LPG process rather than a strict LP process like many of its competitors. To have its cake and eat it too, NVIDIA added a fifth Cortex A9 to Tegra 3 built using LP transistors (hence the LPG process, G transistors in a sea of LP). This fifth core would only be active during the lightest of workloads and be limited in frequency (500MHz). If your phone/tablet is idle, the four higher performance A9s power down and only the fifth companion core remains active.