AMD’s Ryzen processors are renowned for their exceptional performance and efficiency, achieved through innovative architectural designs. At the heart of these processors lies a fundamental building block known as the CCX (Core Complex). This article delves into the intricacies of AMD’s CCX, exploring its definition, composition, and significance in the Ryzen processor architecture.
Key Facts
- Definition: A CCX (Core Complex) is a quad-core or octa-core CPU chiplet with a shared L3 cache[3].
- Composition: Each CCX consists of four CPU cores and their associated CPU caches.
- L3 Cache: Each CCX has its own L3 cache, with a size of 16 MB.
- Infinity Fabric: AMD’s Infinity Fabric technology connects multiple CCXes together to create Ryzen processors.
- Ryzen 3000-Series: In the Ryzen 3000-series processors, CCX refers to a four-core grouping inside each core chiplet die (CCD).
- L3 Cache Sharing: CCXs share the L3 cache, and the amount of L3 cache per CCX depends on the specific CPU model.
- Ryzen 5000-Series: With the Zen 3 based Ryzen 5000-series processors, AMD introduced an 8-core CCD (or CCX) with access to the entire 32MB of cache on the die, resulting in lower core-to-core latency and wider cache bandwidth.
Definition of CCX
A CCX, short for Core Complex, is a fundamental unit of AMD’s Ryzen processors, comprising four or eight CPU cores along with their associated CPU caches (L1, L2, and L3) [3]. These CCXes serve as the basic building blocks for constructing high-core-count Ryzen processors.
Composition of CCX
Each CCX is composed of four CPU cores, each equipped with its own L1 and L2 caches. Additionally, each CCX features a shared L3 cache, which is accessible by all four cores within the CCX. The size of the L3 cache varies depending on the specific Ryzen processor model.
Infinity Fabric Interconnect
AMD’s Infinity Fabric technology plays a crucial role in connecting multiple CCXes to form a cohesive Ryzen processor. This high-speed interconnect enables efficient communication and data transfer between CCXes, ensuring optimal performance and minimizing latency.
Ryzen 3000-Series Processors
In the Ryzen 3000-series processors, the CCX refers to a four-core grouping within each core chiplet die (CCD). Each CCD comprises two CCXes, resulting in a total of eight cores per CCD. This design allows for the creation of Ryzen processors with varying core counts, from 6 cores (with one CCD and one disabled CCX) to 16 cores (with two CCDs and four enabled CCXes).
L3 Cache Sharing
CCXes within a Ryzen processor share the L3 cache, providing all cores with access to a common pool of high-speed memory. The amount of L3 cache allocated to each CCX depends on the specific CPU model, with higher-core-count processors typically featuring larger L3 caches.
Ryzen 5000-Series Processors
With the introduction of the Zen 3 based Ryzen 5000-series processors, AMD implemented a significant architectural change in the CCX design. In these processors, each CCD comprises an 8-core CCX with access to the entire 32MB of cache on the die. This modification resulted in lower core-to-core latency, improved cache bandwidth, and overall enhanced performance, particularly in gaming workloads.
Conclusion
AMD’s CCX architecture is a fundamental aspect of Ryzen processors, enabling the creation of high-core-count CPUs with exceptional performance and efficiency. Through the innovative use of Infinity Fabric interconnect and shared L3 cache, CCXes provide a scalable and cohesive foundation for Ryzen processors, catering to a wide range of computing needs.
References
[1] https://www.nas.nasa.gov/hecc/support/kb/amd-rome-processors_658.html
[2] https://www.tomshardware.com/reviews/amd-ccx-definition-cpu-core-explained,6338.html
[3] https://www.hardwaretimes.com/amd-ccd-and-ccx-in-ryzen-processors-explained/
FAQs
What is a CCX CPU?
A CCX (Core Complex) is a fundamental building block of AMD’s Ryzen processors, comprising four or eight CPU cores along with their associated CPU caches (L1, L2, and L3).
What is the role of CCX in Ryzen processors?
CCXes serve as the basic units for constructing high-core-count Ryzen processors. They enable efficient communication and data transfer between CPU cores, resulting in optimal performance and minimized latency.
How are CCXes connected in Ryzen processors?
CCXes are interconnected via AMD’s Infinity Fabric technology, a high-speed interconnect that facilitates efficient communication and data transfer between CCXes, ensuring optimal performance and minimizing latency.
How do CCXes affect the performance of Ryzen processors?
The number of CCXes and the cores within each CCX directly influence the overall core count and performance of Ryzen processors. Processors with more CCXes and cores typically offer higher performance, particularly in multi-threaded applications.
How does the CCX design benefit Ryzen processors?
The CCX design provides several benefits to Ryzen processors, including scalability, modularity, and improved performance. It allows AMD to create processors with varying core counts to cater to different user needs and enables more efficient use of silicon, resulting in better performance and power efficiency.
What is the difference between CCX in Ryzen 3000 and Ryzen 5000 series processors?
In Ryzen 3000-series processors, each CCX comprises four cores, while in Ryzen 5000-series processors, each CCX comprises eight cores. Additionally, Ryzen 5000-series processors feature a larger L3 cache and an improved Infinity Fabric interconnect, resulting in lower core-to-core latency and enhanced performance.
How many CCXes are there in a Ryzen processor?
The number of CCXes in a Ryzen processor varies depending on the specific model. Ryzen processors can have one or two CCDs, and each CCD comprises two CCXes. Therefore, Ryzen processors can have two, four, or eight CCXes.
How does the CCX design impact gaming performance?
The CCX design can impact gaming performance by affecting core-to-core latency and cache access times. Games that are heavily reliant on inter-core communication and fast memory access may benefit from processors with fewer CCXes and larger L3 caches.