ARM Cortex-X4

The ARM Cortex-X4 is a high-performance CPU core from Arm, released in 2023 as part of Arm's "total compute solution." It serves as the successor of ARM Cortex-X3. X-series CPU cores generally focus on high performance, and can be grouped with other ARM cores, such as ARM Cortex-A720 or/and ARM Cortex-A520 in a System-on-Chip (SoC).

Architecture changes in comparison with ARM Cortex-X3
The processor implements the following changes: Performance claims:
 * micro-op (MOP) cache removed (previously 1.5k entries)
 * Decode width: 10
 * Rename / Dispatch width: 10 (increased from 8)
 * Reorder buffer (ROB): 384 entries (increased from 320)
 * Execution ports: 21 (increased from 15)
 * Pipeline length: 10 (increased from 9)
 * Up to 2 MiB of private L2 cache (increased from 1 MiB)
 * DSU-120
 * Up to 14 cores (up from 12 cores)
 * Up to 32 MiB of shared L3 cache (increased from 16 MiB)
 * ARMv9.2
 * 15% peak performance improvement over the Cortex-X3 in smartphones (3.4GHz, 2MB L2, 8MB L3).
 * 13% IPC uplift over the Cortex-X3, when based on the same process, clock speed, and L3 cache (but 2 MiB L2 vs 1 MiB L2) setup (also known as ISO-process).

Usage

 * MediaTek Dimensity 9300/9300+


 * Qualcomm Snapdragon 8 Gen 3 (2023)
 * Google Tensor G4