IBM z15 (microprocessor)


The z15 is a microprocessor made by IBM for their IBM Z mainframe computers, announced on September 12, 2019.

Description

The Processor Unit chip has 12 cores. The z15 cores support two-way simultaneous multithreading.
The cores implement the CISC z/Architecture with a superscalar, out-of-order pipeline. New in z15 is an on-chip Nest Accelerator Unit, shared by all cores, to accelerate compression.
The cache is doubled from the previous generation z14, while the "L4 Cache increased from 672MB to 960MB, or +43%" with the new add-on chip System Controller SCM. Both it and all levels of cache in the main processor from level 1 use eDRAM, instead of the traditionally used SRAM. "A five-CPC drawer system has 4800 MB of shared L4 cache."