Jaguar (microarchitecture)

Lore & Background

The Jaguar microarchitecture was designed by AMD as a low-power successor to the Bobcat Family, introduced in 2013 and succeeded by the Puma architecture in 2014. It is a two-way superscalar design with out-of-order and speculative execution. Each core has 32 KiB instruction and 32 KiB data L1 cache with parity error detection, while a 16-way unified L2 cache of 1–2 MiB is shared by two or four cores and protected by error correcting code. The FPU datapath width was increased to 128-bit, and a hardware integer divider was added. Improvements over Bobcat include over 10% increase in clock frequency, over 15% improvement in instructions per clock, and support for SSE4.1, SSE4.2, AES, CLMUL, MOVBE, AVX, F16C, and BMI1. The microarchitecture integrates a Fusion controller hub as a SoC and includes a Video Coding Engine. Jaguar does not feature clustered multi-thread (CMT), meaning execution resources are not shared between cores.

Reader's Guide

Jaguar's significance lies in its role as a versatile low-power microarchitecture used across consumer, server, and embedded markets, as well as in major gaming consoles. AMD's Semi-Custom Business Unit leveraged Jaguar for custom processors in the PlayStation 4 and Xbox One, which featured more powerful GPUs than AMD's own commercially available Jaguar APUs. The microarchitecture appeared in four product families: Kabini for notebooks and mini PCs, Temash for tablets, Kyoto for micro-servers, and the G-Series for embedded applications. In 2017, a derivative of Jaguar was announced in the APU of Microsoft's Xbox One X (Project Scorpio), described as a 'customized' derivative with eight cores clocked at 2.3 GHz. The Puma successor to Jaguar was released in 2014, targeting entry-level notebooks and tablets. Jaguar's integration of memory controller, Fusion controller hub, and support for DDR3L memory with ECC in server variants made it suitable for a range of power-constrained applications.

Did You Know?

• Jaguar is used in SoCs for both the PlayStation 4 and Xbox One, with more powerful GPUs than AMD's own commercial Jaguar APUs.
• The L2 cache in Jaguar is protected from errors by error correcting code.
• A derivative of Jaguar was used in the Xbox One X APU, with eight cores clocked at 2.3 GHz.