According to latest details, AMD’s CPU complex units are in fact divisible which makes it possible to create 6-core Ryzen CPUs from the base Zen die. Other reports have also hit the web which not confirm existence of hexa-core models but also reveal their clock speeds.
6-core Ryzen CPUs are technically feasible as CCX is Divisible
We have been hearing multiple reports regarding whether the 6-core model will be part of AMD’s upcoming Ryzen processor family. Recently, a report from Zolkorn.com claimed that there will be no 6-core Ryzen CPUs coming out, but the eight-core, 12-thread parts instead, with SMT disabled.
The reason behind this is because the quad-core CCX (CPU complex) units that make up Ryzen processors are indivisible. This means you can either get a full-blown eight-core parts, or quad-core parts with one CCX disabled.
However, only a day after this was rumored, another report popped up which claimed that 6-core Ryzen model is real and comes with SMT enabled which works out to 12 logical CPUs. This came via Canard PC Hardware which confirms at least one 6-core configuration is being internally tested by AMD.
Today, folks over at IO-Tech have also confirmed through their sources that the development of 6-core Ryzen CPUs is technically feasible indeed. More specifically, the Ryzen CCX is divisible: it is possible to disable individual CPU cores together with dedicated L2 cache without affecting the shared L3 cache.
In other words, each CPU-complex can be used in full 8 MB L3 cache, half 4 MB cache, or it can be completely disabled. Based on the overall architecture design, the basic rule of thumb is that a Ryzen CPU should have two CCXs, both of which connected to 3 cores and full 8 MB of L3 cache, which would give a hexa-core, 16 MB L3 design.
Here’s an illustration of a 6-core Ryzen CPU block diagram:
So it’s entirely possible for AMD to create 6-core models from the base Zen die. If it doesn’t, it might be due to other reasons, not because of the technical limitation of CCX.
6-core Ryzen Leaked with 3.3GHz Base and 3.7GHz Boost clock
A new leak by VideoCardz not only confirms the 6-core Ryzen CPU but also reveals its clock speeds. Spotted in a benchmark entry, the CPU is codenamed “ZD3301BBM6IF4_37/33_Y” and is said to be close to final version.
The alleged 6-core Ryzen model is clocked at 3.3GHz base and 3.7GHz boost clock speed. The chip features up to 12 MB of L3 cache, while the TDP should be rated under 95W. According to the leak, this could be the base 6-core model and we might see even faster variants as part of the lineup at launch.
AMD has confirmed its Ryzen CPU will launch in early March. We don’t know the exact launch date yet, but it’s expected to happen before March 3.
AMD will release Ryzen-branded “Summit Ridge” family of processors in three distinct tiers: SR7, SR5 and SR3. The top-of-the-line SR7 indicates eight cores and SMT which supports up to 16 threads.
The highest clocked SR7 model will feature 3.6GHz base and 4.0 boost clock frequency. It will rival Intel’s Core i7 line of CPUs (at the respective premium).
The SR5 indicates 6C/12T parts that will go toe to toe against Intel’s i7 line of quad-core, HT-enabled processors. The SR3 will target the entry-level segment with quad-core Ryzen chips.
All AMD Ryzen CPUs feature unlocked base-clock multipliers which would support overclocking right out of the box. In addition to this, processors will come with new boost technologies, including Extended Frequency Range (XFR), Pure Power and Precision Boost, that are part of the SenseMI feature set.