Zen – The evolution of AMD’s brilliant chip architecture

AMD – AMD’s Zen movement has altered it’s fortunes. The Ryzen CPUs are clear winners in the long-drawn CPU duel. And getting better.

By BlueWater Tech

Zen provided the impetus and turnaround to AMD

The Zen innovation is perhaps, the singular, decisive, and most significant move made by AMD. It paved the way for the resurgence of AMD, bringing it from the brink and placing it firmly on the growth track. The arrival of the first Zen-based CPU in March of 2017 served as a refreshing challenge to the then reigning leader in CPU technology. Since then AMD has never looked back. It has thrown up a number of series of superior CPUs that have defied the performance-to-price status quo that had come to be established. To date, AMD’s Zen architecture has continued to offer the best CPU efficiency and capability at affordable prices that continue to surprise many.

The first iteration of Zen

The aptly codenamed CPU architecture, based on a 14nm architecture first came to be used in March 2017. Zen first appeared in the Summit Ridge Ryzen 1000 series of CPUs which received immediate success, putting AMD on the radar of experts. Till the arrival of Zen, Intel was sitting pretty on a massive lead and without any challenge. The Ryzen 1000s upset that with CPU design technology that offered pathbreaking gains, ending the complacency of Intel and putting an end to mere incremental improvements offered to the users who were looking for more.

AMD introduced the first Zen-based CPUs as the most impressive lineup available – the Ryzen 7s with a stunning 52% ramp-up in IPC or Instructions Per Cycle. It’s flagship then, the Ryzen 7 – 1800X featured an 8-core-16-thread arrangement as well as a clock speed range of 3.6 GHz base speed and 4.0 GHz maximum boost speed that assailed the rival chips’ numero uno position. With the adoption of dispersed transistor mounting and multiple gates, AMD’s chips began to get smaller, speedier, and more powerful.

Zen + followed

AMD continued it’s mission of introducing high-performance CPUs making the CPU duel more interesting. With AMD’s release of the next iteration, Zen + it became clear that the short-lived era of conservative improvements in CPU calibre was indeed over, and users were willing to let go of their older processors in favour of the newfound standard of higher multiple cores and threads.

The Zen + generation from AMD brought a contraction in chip size to a 12nm node which was a further boost to technology improvement as it packed more speed and power without raising the energy consumption and heating issues that arise with an increase in CPU performance. Having made a clean break with Zen, AMD chose to retain the core count and focus on overall improvements that gave us the Ryzen 2000 series of CPUs. These “Pinnacle Ridge” 2nd generation Ryzens introduced a new Precision Boost mode which pushed the speeds up to 4.35 GHz in case of the Ryzen 7 – 2700X and which carried a combined L2 + L3 cache of 20 MB and a TDP of 105W.

Zen ‘s Quantum leap

Not satisfied with the incremental growth with the Zen +, which in itself was a winner in the face of rival equivalent chips, AMD came up with a ground-up approach and the architecture design evolved into a pathbreaking chip size of 7nm, which saw an IPC enhancement of 15% over it’s preceding generation. With frequencies, generally less liberal, significantly higher instructions per cycle rate provided a much-appreciated performance boost to the Ryzen 3000 series of CPUs.

Apart from the massive boost to IPC, the Zen 2 chips came with significant upscaling to the boost frequencies. The top rung Ryzen 9 3900X and Ryzen 9 3950X max boost speeds were bolstered up to 4.6 GHz and 5.0 GHz respectively. The truly next-generation Zen 2 version introduced a number of enhancements that produced class-leading outcomes in single as well as multi-thread performance. Other areas it leveraged are latency and power efficiency.

Here are the defining features and specs of the Zen 2 based high-performance Ryzen 3000s,

• Zen 2, at it’s foundation has the fresh groundbreaking 7nm process that lends serious frequency and power efficiency benefits to the Ryzen 3000 series of CPUs.
• It comes with a 15 % gen on gen IPC upscaling, providing significant leverage in the overall performance of the CPU.
• The L3 cache too sees an uplift. The Ryzen 3 3600, for instance, boasts an L3 cache number of 32 MB. That provides a meaningful boost to performance including gaming.
• Relatively massive core counts – 6cores- 12 threads for the Ryzen 5 3600 and 16core-32 threads for the Ryzen 9 3950X – give the Zen 2 based Ryzen 3000s an impressive edge in multi-threaded workloads.
• The Zen 2 based Ryzen 3000 s bring along new X570 motherboards, which, are although, not necessary, offer exciting opportunities for enthusiasts.
• The Zen 2 Ryzen CPUs come with PCLe version 4.0 and provide for 24 PCLe lanes.
• The CPUs come with Power Boost Overdrive giving the chips an edge in graphics and gaming.

Zen 3 – the next logical step up

Zen was further refined and optimised to arrive at the current ( at the time of writing) king among mainstream CPUs – the Zen 3 based Ryzen 5000s. It is a result of re-engineering of the successful Zen 2 with a major update to the CCX which rises up to 8 cores per CCX. In a now, traditional fashion, the Zen 3 architecture sees an upscaling in IPC of up to 19 % gen on gen, which puts the CPUs in a high-performance orbit. The Zen 3 features that matter are,

• A significant aspect that is upscaled is the IPC or Instructions Per Cycle. It enables the processor to attain higher productivity levels owing to Zen 3. 
• The Zen 3 based Ryzen lineup of the 5000 series of CPUs continue with the pathbreaking 7nm microarchitecture which forms the standard for future growth trajectories.
• Zen 3 brings favourable latency drops owing to the increased L3 cache. The unified L3 cache of 32 MB also results in lower inter-core latency.
• The Zen 3 based 5000 series of CPUs offers leadership performance in the single-core areas.
• The Zen 3 chips come with a higher number of cores and threads. The 5000 series of Ryzen processors offer superior performance in multiple core and thread applications too, compared to it’s rivals.
• The TDP story continues to reveal excellent system resilience. The Ryzen 5000 series of CPUs support favourable heating /cooling numbers indicating efficiency in energy consumption leading to impressive overall CPU performance. TDP numbers range from 65 W in case of the Ryzen 5- 5600X, to 105 W in case of the Ryzen 9-5950 X.

Final thoughts

The latest iteration of Zen – Zen 3 – has consolidated AMD’s leading position in the CPU landscape with the Ryzen 5000 series of CPUs offering class-leading performance in mainstream computing. And if industry rumours and AMD news trickling in are to be considered, the emergence of Zen 4 in the near future, is set to maintain the commanding position of AMD.

AMD has been able to accommodate more cores and features per unit of chip real estate, all along succeeding in keeping excessive system heating at bay. It will be hardly surprising if the Ryzens continue to lead in the CPU duel with Intel. Further, AMD’s shrinking nanometer trajectory may be set to get further traction. This will help uplift its performance if and when the rumoured 5nm Zen 4 based Ryzen CPUs arrive.