Sandy Bridge is the codename for a microarchitecture developed by Intel beginning in 2005 for central processing units in computers to replace the Nehalem microarchitecture. Intel demonstrated a Sandy Bridge processor in 2009, and released first products based on the architecture in January 2011 under the Core brand.Originally, implementations targeted a 32 nanometer manufacturing process based on planar double-gate transistors. Subsequent products, codenamed Ivy Bridge, use a 22 nanometer process. The Ivy Bridge die shrink, known in the Intel Tick-Tock model as the "tick", is based on 3D tri-gate transistors. Intel demonstrated Ivy Bridge processors in 2011.