5.1 POWER8TM: A 12-core server-class processor in 22nm SOI with 7.6Tb/s off-chip bandwidth

The 12-core 649mm
²
POWER8™ leverages IBM's 22nm eDRAM SOI technology [1], and microarchitectural enhancements to deliver up to 2.5× the socket performance [2] of its 32nm predecessor, POWER7+™ [3]. POWER8 contains 4.2B transistors and 31.5μF of deep-trench decoupling capacitance. Three thin-oxide transistor V
t
s are used for power/performance tuning, and thick-oxide transistors enable high-voltage I/O and analog designs. The 15-layer BEOL contains 5–80nm, 2–144nm, 3–288nm, and 3–640nm pitch layers for low-latency communication as well as 2–2400nm ultra-thick-metal (UTM) pitch layers for low-resistance distribution of power and clocks.