With Ryzen, the smallest CPU is a single CCD, with 2 CCXs, effectively an eight-core processor. How on earth do they sell quad-cores and Hexa-cores, then? This is where the real advantage of the chiplet design shows itself.
No matter how high silicon yields are, there’s always a defect rate. And on a newer process like the 7nm process, that defect rate can be 20% or even higher. Every core on a processor has a chance of being defective.
So, the more cores on a single die, the more likely it is that at least one core is defective.
In Intel’s monolithic die this means throwing out the whole CPU if even one core is defective. This causes Intel’s manufacturing cost scale to scale exponentially up with core count. An 8-core Intel part costs them far more than twice as much as a quad-core.
The anatomy of a Ryzen Gen 3: Salvage parts and core scaling
With Ryzen core count scales near-linearly with price. Since each Ryzen CPU is made up of CCXs (quad-core units), AMD just has to watch yields on that quad-core building block.
Wastage is far, far lower than for a monolithic eight-core or sixteen-core die. And even when individual CCXs have defects, AMD doesn’t throw them away. Instead, they disable one or more cores to help create cheaper SKUs.
For instance, the hexacore Ryzen 5 3600, a price-performance champion, has the same core layout as the pricier, octa-core Ryzen 7 3700. It has the faulty CCX disabled on each CCD, for a total of 6 cores. By utilising salvage parts and multi-chip scaling, AMD keeps prices low, even when core counts rise.
So, Intel uses large, single dies, while AMD makes use of multiple, smaller dies put together. It’s hard to understate how significant an impact this has had on the CPU market over the past two years.
Exactly how did Ryzen shake up the market?
Since Intel’s Sandy Bridge (2011) it has been content to sell mainstream quad-core CPUs with relatively high single-threaded performance.
AMD emulated Intel’s going multi-core with Bulldozer, but that experiment failed miserably.
Its failure lead to AMD’s success. Its new Ryzen chiplet architecture was able to offer significantly improved instructions per cycle (IPC).
With Ryzen Gen 1, AMD could offer more cores and more threads at every single price-point than Intel.
- The Ryzen 3 1200, with four-cores and four-threads, went up against dual-core i3 and Pentium.
- The Ryzen 5 1600 had six cores and 12 threads chasing Intel i5 buyers.
This was unprecedented: Intel’s i7s were quad-core eight-threads, and only its ultra-premium HEDT parts offered more than four cores.
Intel still managed to deliver better single-threaded performance, and for some time, its processors were still meaningfully better for gaming.
Ryzen Gen 3 changed that. IPC improvements meant that clock-for-clock, it outperformed Coffee Lake. Ryzen’s multiple ‘parts’ clock lower than Intel counterparts offsetting this advantage slightly.
With no noticeable gaming advantage to Intel, buying Ryzen simply became a no-brainer. In DIY markets like South Korea AMD has over 50% Ryzen market share – numbers AMD hasn’t hit in over a decade.