Welcome Stranger to OCC!Login | Register

AMD Ryzen 5 1600X & 1500X Processor Review

» Discuss this article (3)

AMD Ryzen 5 1600X & 1500X Processor Closer Look:

When digging into the technical details, I will let AMD do the driving here to eliminate any confusion.


"On the performance side, the Zen microarchitecture represents a quantum leap in core execution capability versus AMD’s previous desktop designs. Notably, the Zen architecture features a 1.75X larger instruction scheduler window and 1.5X greater issue width and resources2; this change allows “Zen” to schedule and send more work into the execution units. Further, a new micro-op cache allows “Zen” to bypass L2 and L3 cache when utilizing frequently-accessed micro operations. Zen also gains a neural network-based branch prediction unit allows the “Zen” architecture to be more intelligent about preparing optimal instructions and pathways for future work. Finally, products based on the “Zen” architecture may optionally utilize SMT to increase utilization of the compute pipeline by filling app-created pipeline bubbles with meaningful work. Together, these changes invest elite-caliber single-threaded capabilities into the heart of Zen.



A high-performance engine requires fuel, and the Zen architecture’s throughput characteristics deliver in this regard. Chief amongst the changes are major revisions to cache hierarchy with dedicated 64KB L1 instruction and data caches, 512KB dedicated L2 cache per core, and 8MB of L3 cache shared across four cores. This cache is augmented with a sophisticated learning prefetcher that speculatively harvests application data into the caches so they are available for immediate execution. Altogether, these changes establish lower level cache nearer to the core netting up to 5X greater cache bandwidth into a core.



Beyond adopting the more power efficient 14nm FinFET process, the Zen architecture specifically utilizes the density-optimized version of the Global Foundries 14nm FinFET process. This permits for smaller die sizes and lower operating voltages across the complete power/performance curve. The Zen architecture also incorporates AMD’s latest low power design methodologies, such as: the previously mentioned micro-op cache to reduce power-intensive faraway fetches; aggressive clock gating to zero out dynamic power consumption in minimally utilize regions of the core; and a stack engine for low-power address generation into the dispatcher. It is in this realm, especially, that the power management wisdom of AMD’s APU teams shine through to impart in “Zen” the ability to scale from low-wattage mobile to HEDT configurations.



Scalability in the “Zen” architecture starts with the CPU Complex (CCX), a natively 4C8T module. Each CCX has 64K L1 I-cache, 64K L1 D-cache, 512KB dedicated L2 cache per core, and 8MB L3 cache shared across cores. Each core within the CCX may optionally feature SMT for additional multi-threaded capabilities. More than one CCX can be present in a “Zen”-based product, wherein the AMD Ryzen™ processor features two CCXes consisting of 8 cores and 16 threads (total). Individual cores within the CCX may be disabled by AMD, and the CCXes communicate across the high-speed Infinity Fabric. This modular design allows AMD to scale core, thread, and cache quantities as necessary to target the full spectrum of the client, server, and HPC market.


The Infinity Fabric, meanwhile, is a flexible and coherent interface/bus that allows AMD to quickly and efficiently integrate a sophisticated IP portfolio into a cohesive die. These assembled pieces can utilize the Infinity Fabric to exchange data between CCXes, system memory, and other controllers (e.g. memory, I/O, PCIe®) present on the AMD Ryzen™ SoC design. The Infinity Fabric also gives the “Zen” architecture powerful command and control capabilities, establishing a sensitive feedback loop that allows for real-time estimations and adjustments to core voltage, temperature, socket power draw, clockspeed and more. This command and control functionality is instrumental to AMD SenseMI technology.




First and foremost, it is important to understand that each AMD Ryzen™ processor has a distributed “smart grid” of interconnected sensors that are accurate to 1mA, 1mV, 1mW, and 1°C with a polling rate of 1000/sec. These sensors generate vital telemetry data that feed into the Infinity Fabric control loop, and the control loop is empowered to make real time adjustments to AMD Ryzen™ processor’s behavior based on current and expected future operating conditions. AMD SenseMI is a package of five related “senses” that rely on sophisticated learning algorithms and/or the command-and-control functionality of the Infinity Fabric to empower AMD Ryzen™ processors with machine intelligence (MI).3 This intelligence is utilized to fine-tune the performance and power characteristics of the cores, manage speculative cache fetches, and perform AI-based branch prediction.

Pure Power: The distributed network of smart sensors that drive Precision Boost can do double duty to streamline processor power consumption with any given workload. And for next-level brilliance: telemetry data from the Pure Power optimization loop allows each AMD Ryzen™ processor to inspect the unique characteristics of its own silicon to extract individualized power management.


Precision Boost:

Using current/temperature/load data from the Infinity Fabric, Precision Boost modulates an AMD Ryzen™ processor’s clockspeeds in exacting 25MHz steps. The granular clockspeed control gives AMD Ryzen™ processors greater operational freedom to press core frequency closer to the ideal frequency target, and allows for finer dithering at that ideal target. Reviewers should expect a clockspeed plot to be reminiscent of a GPU, rather than a square wave, and this behavior is instrumental in sustaining a consistently high clockspeed.


Extended Frequency Range (XFR):

Rewards users who build or buy AMD Ryzen™ processor-based systems with great cooling. Available on select AMD Ryzen™ processor models with the –X suffix, XFR lifts the maximum Precision Boost frequency—beyond the ordinary limits—in the presence of premium system and processor cooling.3 This is achieved by reading and forecasting AMD Ryzen™ processor’s distance to junction thermal limits, then converting available headroom into additional frequency.


Neural Net Prediction:

A true AI inside every AMD Ryzen™ processor harnesses a neural network to do real-time learning of an application’s behavior and speculate on its next moves. The predictive AI readies vital CPU instructions so the processor is always primed to tackle a new workload.


Smart Prefetch:

Sophisticated learning algorithms understand the internal patterns and behaviors of applications and anticipate what data will be needed for fast execution in the future. Smart Prefetch predictively pre-loads that data into large caches on the AMD Ryzen™ processor to enable fast and responsive computing."


This should give you a basic intro into the clean slate design AMD used with the Summit Ridge Ryzen processors. Everything looks promising, but the proof, as they say, is in the pudding. 

Related Products
Random Pic
© 2001-2017 Overclockers Club ® Privacy Policy
Elapsed: 0.1289799213   (xlweb1)