In this review article, we will continue our AMD Ryzen™ saga with another member of the seventh series which is the Ryzen 7 1700. The Ryzen 7 1700 was built, as the 7 1800X with eight physical cores, 16 threads and the rated TDP was lowered to an amazing value of 65W (for an octa-core SKU). The product does sport a MSRP of $329 and is aimed to go against the Intel Core i7 7700K Kaby Lake mainstream CPU.
The product naming from the Ryzen series has been carefully thought out in order to cover all market segments with SKU such as Ryzen 5 and Ryzen 3:
This SKU is also integrating the Zen architecture, which focuses on four different key areas: performance, throughput, efficiency but also scalability.
Regarding performance, the new Zen microarchitecture represents a very big leap in core execution capability versus the previous designs from the same company: Zen come with a 1.75X larger instruction scheduler window and 1.5X greater issue width and resources. This practically allows Zen to schedule and send more work into the EUs. Thanks to a new micro-op cache, Zen is allowed to bypass L2 and L3 caches when using frequently accessed micro-operations. The neural network-based branch prediction unit from the Zen microarchitecture does allow for more intelligent preparation of optimal instructions and pathways for future work.
Changes have been also made regarding the cache hierarchy with dedicated 64KB L1 instruction and data caches, we do have 512KB dedicated L2 cache per core and 8MB of L3 cache shared across four cores. The cache is enhanced with a learning prefetcher that speculatively harvests application data into the caches so they are practically available for immediate execution. These changes are assuring up to 5X greater cache bandwidth into a core. This type of design enhances the Zen architecture's throughput.
When talking about efficiency, the new Ryzen processors are built on the more power-efficient 14nm FinFET process; in more detail, the Zen architecture is using the density-optimized version of the Global Foundries 14nm FinFET process and this fact permits for smaller die sizes and lower operating voltages. The new Zen microarchitecture does incorporate some of the latest low-power design technologies:
-micro-op cache for reducing power-intensive faraway fetches
-aggressive clock gating to zero out dynamic power consumption in minimally utilized regions of the core
-a stack engine for low-power address generation into the dispatcher.
Moving on to the scalability aspect, Zen architecture does start with the CCX (CPU Complex) which is a native 4C8T module; each CCX does come with 64K L1 I-cache, 64K L1 D-cache, 512KB of dedicated L2 cache per core and 8MB of L3 cache shared across all cores. Each core that is contained in the CCX may optionally come with SMD for additional threads.