The ARM Cortex-X3 is the third generation X-series high-performance CPU core from Arm.

It forms part of Arm's Total Compute Solutions 2022 (TCS22) along with Arm's Cortex-A715, Cortex-A510, Immortalis-G715 and CoreLink CI-700/NI-700.

Architecture changes in comparison with ARM Cortex-X2

The processor implements the following changes:

  • Decode width: 6 (increased from 5)
  • Rename / Dispatch width: 8
  • micro-op (MOP) cache: 1.5k entries (reduced from 3k)
  • Reorder buffer (ROB): 320 entries (increased from 288)
  • Execution ports: 15
  • Pipeline length: 9 (reduced from 10)

Performance claims:

  • 25% peak performance improvement over the ARM Cortex-X2 in smartphones

(3.3GHz, 1MB L2, 8MB L3).

  • 11% IPC uplift over the ARM Cortex-X2, when based on the same process,

clock speed, and cache setup (also known as ISO-process).

Usage

Architecture comparison

"Prime" core

uArchCortex-A78Cortex-X1Cortex-X2Cortex-X3Cortex-X4Cortex-X925
Code nameHerculesHeraMatterhorn-ELPMakalu-ELPHunter-ELPBlackhawk
ArchitectureARMv8.2ARMv9ARMv9.2
Peak clock speed~3.0 GHz~3.3 GHz~3.4 GHz~3.8 GHz
Decode width45610
Dispatch6/cycle8/cycle10/cycle
Max in-flight2x 1602x 2242x 2882x 3202x 3842x 768
L0 (Mops entries)1536307215360
L1-I + L1-D32+32 KiB64+64 KiB
L2128–512 KiB0.25–1 MiB0.5–2 MiB2–3 MiB
L30–8 MiB0–16 MiB0–32 MiB

See also