What is “ZEN2”?
AMD’s Zen2 (“Matisse”) is the “true” 2nd generation ZEN core on 7nm process shrink while the previous ZEN+ (“Pinnacle Ridge”) core was just an optimisation of the original ZEN (“Summit Ridge”) core that while socket compatible it introduces many design improvements over both previous cores. An APU version (with integrated “Navi” graphics) is scheduled to be launched later.
While new chipsets (500 series) will also be introduced and required to support some new features (PCIe 4.0), with an BIOS/firmware update older boards may support them thus allowing upgrades to existing systems adding more cores and thus performance. [Note: older boards will not be enabled for PCIe 4.0 after all]
The list of changes vs. previous ZEN/ZEN+ is extensive thus performance delta is likely to be very different also:
- Built around “chiplets” of up to 2 CCX (“core complexes”) each of 4C/8T and 8MB L3 cache (7nm)
- Central I/O hub with memory controller(s) and PCIe 4.0 bridges connected through IF (“Infinity Fabric”) (12nm)
- Up to 2 chiplets on desktop platform thus up to 2x2x4C (16C/32T 3950X) (same amount as old ThreadRipper 1950X/2950X)
- 2x larger L3 cache per CCX thus up to 2x2x16MB (64MB) L3 cache (3900X+)
- 20 PCIe 4.0 lanes (2x higher transfer rate over PCIe 3.0)
- 2x DDR4 memory controllers up to 3200Mt/s official (4266Mt/s max)
To upgrade from Ryzen+/Ryzen1 or not?
Micro-architecturally there are more changes that should improve performance:
- 256-bit (single-op) SIMD units 2x Fmacs (fixing a major deficiency in ZEN/ZEN+ cores)
- TLB (2nd level) increased (should help out-of-page access latencies that are somewhat high on ZEN/ZEN+)
- Memory latencies claim to be reduced through higher-speed memory (note all requests go through IF to Central I/O hub with memory controllers)
- Load/Store 32bytes/cycle (2x ZEN/ZEN+) to keep up with the 256-bit SIMD units (L1D bandwidth should be 2x)
- L3 cache is 2x ZEN/ZEN+ but higher latency (cache is exclusive)
- Infinity Fabric is 512-bit (2x ZEN/ZEN+) and can run 1x or 1/2x vs. DRAM clock (when higher than 3733Mt/s)
- AMD processors have thankfully not been affected by most of the vulnerabilities bar two (BTI/”Spectre”, SSB/”Spectre v4″) that have now been addressed in hardware.
- HWM-P (hardware performance state management) transitions latencies reduced (ACPI/CPPCv2)
In this article we test CPU core performance; please see our other articles on:
- AMD Ryzen3 5800X Review & Benchmarks – CPU 8-core/16-thread Performance
- AMD Ryzen2 3900X Review & Benchmarks – CPU 12-core/24-thread Performance
- AMD Ryzen2 3700X Review & Benchmarks – Cache and Memory Performance
- AMD Ryzen Threadripper 3970X, 3960X Review & Benchmarks – CPU Performance
We are comparing the middle-of-the-range Ryzen2 (3700X) with previous generation Ryzen+ (2700X) and competing architectures with a view to upgrading to a mid-range high performance design.
|CPU Specifications||AMD Ryzen 9 3900X (Matisse)
||AMD Ryzen 7 3700X (Matisse)||AMD Ryzen 7 2700X (Pinnacle Ridge)||Intel i9 9900K (Coffeelake-R)||Intel i9 7900X (Skylake-X)||Comments|
|Cores (CU) / Threads (SP)||12C / 24T||8C / 16T||8C / 16T||8C / 16T||10C / 20T||Core counts remain the same.|
|Topology||2 chiplets, each 2 CCX, each 3 cores (1 disabled) (12C)||1 chiplet, 2 CCX, each 4 cores (8C)||2 CCX, each 4 cores (8C)||Monolithic die||Monolithic die||1 chiplet+1 sio rather than 1 die|
|Speed (Min / Max / Turbo)||3.8 / 4.6GHz||3.6 / 4.4GHz||3.7 / 4.2GHz||3.6 / 5GHz||3.3 / 4.3GHz||3700x base clock is lower than 2700x but turbo is higher|
|Power (TDP / Turbo)||105 / 135W||65 / 90W||105 / 135W||95 / 135W||140 / 308W||TDP has been greatly reduced vs. ZEN+|
|L1D / L1I Caches||12x 32kB 8-way / 12x 32kB 8-way||8x 32kB 8-way / 8x 32kB 8-way||8x 32kB 8-way / 8x 64kB 4-way||8x 32kB 8-way / 8x 32kB 8-way||10x 32kB 8-way / 10x 32kB 8-way||L1I has been halved but better no. ways|
|L2 Caches||12x 512kB (6MB) 8-way||8x 512kB (4MB) 8-way||8x 512kB (4MB) 8-way||8x 256kB (2MB) 16-way||10x 1MB (10MB) 16-way||No changes to L2|
|L3 Caches||2x2x 16MB (64MB) 16-way||2x 16MB (32MB) 16-way||2x 8MB (16MB) 16-way||16MB 16-way||13.75MB 11-way||L3 is 2x ZEN+|
|Mitigations for Vulnerabilities||BTI/”Spectre”, SSB/”Spectre v4″ hardware||BTI/”Spectre”, SSB/”Spectre v4″ hardware||BTI/”Spectre”, SSB/”Spectre v4″ software/firmware||RDCL/”Meltdown”, L1TF hardware, BTI/”Spectre”, MDS/”Zombieload”, software/firmware||RDCL/”Meltdown” , L1TF, BTI/”Spectre”, MDS/”Zombieload”, all software/firmware||Ryzen2 addresses the remaining 2 vulnerabilities while Intel was forced to add MDS to its long list…|
|Microcode||MU-8F7100-11||MU-8F7100-11||MU-8F0802-04||MU-069E0C-9E||MU-065504-49||The latest microcodes included in the respective BIOS/Windows have been loaded.|
|SIMD Units||256-bit AVX/FMA3/AVX2||256-bit AVX/FMA3/AVX2||128bit AVX/FMA3/AVX2||256-bit AVX/FMA3/AVX2||512-bit AVX512||ZEN2 SIMD units are 2x wider than ZEN+|
We are testing native arithmetic, SIMD and cryptography performance using the highest performing instruction sets (AVX2, FMA3, AVX, etc.). Ryzen2 supports all modern instruction sets including AVX2, FMA3 and even more like SHA HWA but not AVX-512.
Results Interpretation: Higher values (GOPS, MB/s, etc.) mean better performance.
Environment: Windows 10 x64, latest AMD and Intel drivers. 2MB “large pages” were enabled and in use. Turbo / Boost was enabled on all configurations. All mitigations for vulnerabilities (Meltdown, Spectre, L1TF, MDS, etc.) were enabled as per Windows default where applicable.
ZEN2’s 256-bit wide SIMD units are a big upgrade and show their power in every SIMD workload; otherwise there is only minor improvement.
SiSoftware Official Ranker Scores
- AMD Ryzen 9 3950X 16-Core/32-Threads
- AMD Ryzen 9 3900X 12C/24T
- AMD Ryzen 9 3900XT 12-Core/24-Threads
- AMD Ryzen 7 3700X 8C/16T
- AMD Ryzen 7 3800XT 8-Core/16-Threads
- AMD Ryzen 5 3600X 6C/12T
- AMD Ryzen 5 3600 6C/12T
Final Thoughts / Conclusions
Executive Summary: For SIMD workloads you really have to upgrade to Ryzen2; otherwise stick with Ryzen+ unless lower power is preferred. 9/10 overall.
The big change in Ryzen2 are the 256-bit wide SIMD units and all vectorised workloads (Multi-Media, Scientific, Image processing, AI/Machine Learning, etc.) using AVX/FMA will greatly benefit – anything between 50-100% which is a significant increase from just one generation to the next.
But for all other workloads (e.g. Financial, legacy, etc.) there is not much improvement over Ryzen+/1 which were already doing very well against competition.
Naturally it all comes at lower TDP (65W vs 95) which may help with overclocking and also lower noise (from the cooling system) and power consumption (if electricity is expensive or you are running it continuously) thus the performance/W(att) is still greatly improved.
Overall the 3700X does represent a decent improvement over the old 2700X (which is no slouch and was a nice upgrade over 1700X due to better Turbo speeds) and should still be usable in older AM4 300/400-series mainboards with just a BIOS upgrade (without PCIe 4.0).
However, while 2700X (and 1700X/1800X) were top-of-the-line, 3700X is just middle-ground, with the new top CPUs being the 3900X and even the 3950X with twice (2x) more cores and thus potentially huge performance rivaling HEDT Threadripper. The goad-posts have thus moved and thus far higher performance can be yours with just upgrading the CPU. The future is bright…