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: ARMv9.2 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) Performance claims: 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).
Architecture comparison
"Prime" core uArchCortex-A78Cortex-X1Cortex-X2Cortex-X3Cortex-X4Cortex-X925Code nameHerculesHeraMatterhorn-ELPMakalu-ELPHunter-ELPBlackhawkArchitectureARMv8.2ARMv9ARMv9.2Peak clock speed~3.0 GHz~3.3 GHz~3.4 GHz~3.8 GHzDecode width45610Dispatch 6/cycle8/cycle10/cycleMax in-flight2x 1602x 2242x 2882x 3202x 3842x 768L0 (Mops entries)1536307215360L1-I + L1-D32+32 KiB64+64 KiBL2 128–512 KiB0.25–1 MiB0.5–2 MiB2–3 MiBL30–8 MiB0–16 MiB0–32 MiB
Usage Google • Tensor G4 MediaTek • Dimensity 9300/9300+ Qualcomm • Snapdragon 8 Gen 3 (2023)
See also ARM Cortex-A520, related high efficient microarchitecture ARM Cortex-A720, related efficient sustained performance microarchitecture Comparison of ARMv8-A cores
References