AMD Launches Ryzen 4000 Series For Laptops: Zen 2 Mobile Unleashed With Big Performance Gains

AMD announced its Zen 2-based Ryzen 4000 series mobile processors a couple of months back at CES 2020. The information disseminated at AMD’s press conference, however, was relatively high-level, and as it turns out, wasn’t quite complete. Since the show, we’ve been made privy to much more information regarding the Ryzen 4000 series mobile line-up, including a couple of new processor models that haven’t been officially disclosed just yet.

Though the Ryzen 4000 series mobile processors won’t be widely available for a few more weeks, some of AMD’s partners are going to begin taking pre-orders for notebooks powered by these new processors. As such, AMD is lifting the veil on additional details and the architectural enhancements and features that make the Ryzen 4000 series what it is – AMD’s strongest mobile processor line-up to date. Or at least it should be; we expect to be able to verify many of AMD’s performance claims with our own independent testing soon. For now though, let's discuss AMD's Ryzen 4000 series and its inner workings in more detail.

What Makes The AMD Ryzen 4000 Series Tick

The AMD Ryzen 4000 series processors are all based on the Zen 2 architecture, similar to the current Ryzen 3000 series desktop processors. We have covered the Zen 2 architecture in detail before, so we won’t be re-hashing it all again here – if you’d like a refresher, please check out some of our previous coverage.


Though it features the same architecture as its desktop (and server) counterparts, AMD points out that the Ryzen 4000 series -- code named Reniour -- was designed for mobile applications from the start. That means power efficiency was paramount to its design goals. AMD claims that all of the enhancements that improve the processor’s IPC were added only if they didn’t come at the expense of power. With Ryzen 4000 series mobile processors, AMD is touting an approximate 25% IPC increase versus Zen 1-based mobile parts, but of course, there are additional benefits that further boost performance and efficiency throughout the chips as well.


Speaking of the chips, the AMD Ryzen 4000 series are the first 7nm x86 mobile processors. They are monolithic, full-featured SoCs, with up to 8-cores / 16-threads. The processors are manufactured on TSMC’s 7nm node, and feature 13 metal layers, with roughly 9.8 billion transistors in total. The die size is approximately 156mm², but the full BGA package is 25mm x 25mm x 1.38mm. If you’re keeping count, the Ryzen 4000 series features nearly 2X the number of transistors of previous-gen Picasso-based AMD mobile processors, but with a 25% smaller die area.

One side benefit of basing all of its products on a single architecture is that it simplifies things for consumers. With Intel’s current mobile platform offerings, users must choose between machines featuring the latest Ice Lake-based processors, with all of the latest graphics enhancements that come by way of the company’s Gen 11 GPU, and Comet Lake, should they want additional CPU cores for content creation or other more-taxing workloads. With AMD's new mobile family, it’s Zen 2 across the board, throughout the top-to-bottom line-up.


AMD is claiming 20% lower SoC power, 2X the perf-per-watt, 5X faster state switching, and an approximate 3.4X improvement in relative power efficiency, in comparison to its mobile platform from 2015. Ryzen 4000 series processors also feature significantly improved iGPU performance. All told, the CPU and GPU related power, performance, and packaging / die-area optimizations should give AMD a solid foundation on which to grab share from Intel in the mobile market, where Intel has historically been lights-out dominant.


In fact, AMD is already claiming upwards of 100+ design wins that will debut through Q1 and later into the year. The company also notes that it is working closely with its partners to ensure a good user experience and that quality components are used in machines featuring its processors. AMD has actually implemented a component assurance program in combination with key system partners, in addition to a new user experience certification. The machines will also undergo continuous validation in an effort to keep the user experience strong throughout the notebook’s useable life, and the inevitable array of updates that get released over time. If AMD or its partners encounter any updates that negatively impact performance or stability, the goal is to work quickly to resolve the issues, before users have to seek out other solutions. AMD plans to “own the notebook experience from end-to-end” moving forward.

Power Efficiency Was Paramount

In addition to all of the power and efficiency benefits that come by way of the Zen 2 architecture and the processors’ leading-edge 7nm manufacturing process, AMD has tweaked a number of other things inside the Ryzen 4000 series to further improve efficiency. AMD's Infinity Fabric, which links all of the IP and functional blocks in the processors together, has been enhanced with finer-grained Dynamic Power Optimization throughout the fabric switches and the bus width between the graphics engine and fabric has doubled, which results in better utilization of available bandwidth. AMD is claiming up to 75% better power efficiency in the fabric, due to these dynamic power optimizations and tuned bandwidth.


The move to support LPDDR4X also results in increased memory bandwidth at lower effective power versus traditional DDR4, and the processors themselves feature more aggressive L3 clock and power gating, I/O power reductions, power optimized SoC clocking circuits, and up to a 5X reduction in CPUOFF latency. AMD doubled the save and restore bus width to reduce entry and exit latency and optimized the power management firmware as well, for roughly a 33% speed-up. Reducing these latencies essentially means cores can be powered off more often, and powered up and down faster, ultimately saving power.

AMD Ryzen 4000 Series I/O Enhancements

AMD has enhanced the Ryzen 4000 series’ I/O configuration as well. The memory controller can support DDR4 memory up to 3200MHz or LPDDR4X at up to 4266MHz. The use of LPDDR4X not only reduces overall power, but offers a big uplift in available bandwidth due to its much higher maximum frequency.


Note that the memory controller’s configuration inside the Ryzen 4000 series is different, depending on which type of memory is being used. When using DDR4, the memory controller is configured as a pair of 64-bit channels, but when using LPDDR4X the partitioning changes to 4 x 32-bit channels.


AMD has also added four PCI Express lanes to the design, to attach additional devices (NVMe drives, WiFi-6 or 5G controllers, etc.) and two USB ports have been added as well. The USB ports are native USB-C and support concurrent USB 3.2 and DisplayPort use (DisplayPort v1.4 – 8.1G HBR3 + DSC). By employing Display Stream Compression (DSC), the Ryzen 4000 series supports two 4K monitors over the USB-C ports when using Multi-Stream Transport (MSC).

Vega-Based Radeon Graphics Enhancements

Although AMD has had, newer Navi-based desktop and mobile discrete GPUs available for some time now, the Ryzen 4000 series mobile processors leverage on-die Vega-based graphics, similar to their predecessors. The graphics engine on the Ryzen 4000 series, however, has been significantly tuned for better efficiency and performance. AMD is claiming up to 59% more performance per Graphics CU, though the maximum number of compute units has been reduced by 20% (the top-end Ryzen 4000 series processors have 8 graphics CUs).


Even with the reduced number of CUs, however, AMD notes that the move down to 7nm has allowed for a roughly 25% increase in frequency. That frequency boost, coupled with the increased bandwidth offered by the wider data fabric and faster LPDDR4X-4266 memory – which offers up to 77% higher peak memory bandwidth – results in higher delivered performance at lower overall power. The top-end Vega graphics configurations will offer 1.8TFLOPs of peak compute performance.


The GPU in the Ryzen 4000 series also features a second-gen Radeon Multimedia Engine with support for hardware-accelerated HDR/ECG (HEVC) encoding and roughly 31% increases in encoding performance with other codecs.

The AMD Ryzen 4000 Series Line-Up

AMD Ryzen 4000 mobile processors will initially consist of U-Series processors for consumer-class thin and lights and H-Series processors for more-powerful gaming systems and content creators. Later in the year, Pro Series Ryzen 4000 series processors will also be coming, which will target the enterprise market with more robust security and management features.


The U-Series flagship, the Ryzen 7 4800U, is an 8-core / 16-thread processor with a max turbo frequency of 4.2GHz and integrated Vega-derived 8-core GPU. As mentioned, that is a lower number of GPU cores than previous-gen AMD mobile processors, but due to the aforementioned architectural enhancements in the GPU and the clock speed benefits of producing the chips at 7nm, AMD is claiming improved graphics performance. The initial Ryzen 4000 U-Series line-up consists of five processors, starting with the 4 core / 4 thread Ryzen 3 4300U, and topping-out with the aforementioned Ryzen 7 4800U.


AMD initially disclosed only two processors in the Ryzen 4000-H series line-up, but there will actually be more. Today AMD is making the Ryzen 9 4900H and 4900HS official, along with HS variants of the previously announced parts. In total, the Ryzen 4000 H-Series lineup will initially consist of six processors, most of which are 8-core / 16-thread parts. Ryzen 9 4900HS, Ryzen 9 4900H, and Ryzen 7 4800H are all 8-core / 16-thread parts, whereas the Ryzen 5 4600H has 6-cores / 12-threads. These H-series processors target somewhat larger notebooks than the U-Series, that cater to gamers and content creators. They have configurable 35- to 45-watt TDPs, though they can TDP-up to 54 watts in some configurations; power and temperature permitting. The 45W Ryzen 9 4900H will being shipping this spring, with a 3.0GHz base clock and 4.3GHz boost clock.

Optimizing Performance For Mobile Platforms

AMD also announced a new feature coming to its mobile platform dubbed SmartShift. SmartShift will allow all-AMD based notebooks (AMD CPU + AMD GPU) to intelligently and dynamically take advantage of all available power and thermal headroom, to optimize the performance between the CPU and GPU.


Instead of a notebook manufacturer arbitrarily allocating a certain percentage of TDP to the CPUs and GPUs in their notebook designs, based on the capabilities of their coolers, AMD's Zen 2 architecture now offers real-time, insight into the power and thermals of its processors. SmartShift can reallocate available TDP headroom on the fly. We saw the technology in action in live demos and – at least according to the tools AMD had on display – you can see the power allocation immediately switch between the CPU and GPU on the fly. AMD is also working with its partners to ensure capable thermal solution designs are used throughout laptop line-ups that feature Ryzen 4000 series mobile processors.


An update to AMD’s Skin Temperature Tracking technology (STT) should also boost overall performance. STT v2 allows for tapering of boost clocks in lockstep with the skin temperature. Thermals diodes are placed in strategic hot-spots throughout the chassis and the readings are passed to the Infinity Fabric through an embedded controller. That data is used to enable longer boosts, provided they don’t negatively impact skin temps. STT v2 works in conjunction with AMD’s previous STAPM (Skin Temperature Aware Power Management) technology, to balance high-boost clocks, with longer boost clocks in line with the chassis’ thermals.


STT v2 also works with discrete GPUs and AMD SmartShift configurations – it's not reserved solely for machines using the integrated Vega-based graphics engine.

Ryzen 4000 Series - Boosting Battery Life

AMD put a major focus on maximizing battery life with its latest mobile platform. Due to the architectural and manufacturing enhancements in the processors, the company was able to get to much lower operating voltages than they have been able to before, with previous-gen processors. In addition, AMD's Ryzen 4000 series is able to get into and out of low power states faster.


As we’ve already mentioned, the Ryzen 4000 series offers 20% lower SoC power, and the width of the bus to save and restore power states has been doubled, but it also features better Idle and Activity detection, along with enhanced power state selection.


A new System Management Controller was critical to enabling these enhancements according to AMD. Ryzen 4000 series mobile processors have a dedicated microcontroller to monitor activity from many parts of the SoC (IP blocks and buses). Observed activity is constantly monitored and the data is used to adjust clock rates and voltages accordingly. Higher utilization, will increase clocks, while low utilization, decreases clocks – within power and thermal limits, of course.


AMD recommended power and thermal profiles target maximum performance when systems are plugged into AC power, and the preference is toward battery life when unplugged. All told, AMD's testing indicates battery life characteristics that are highly competitive with some of the best Intel-based mobile platforms available. Intel wins with some workloads, while AMD wins with others.

Some Words On Ryzen 4000 Series Performance

AMD is claiming superior single-thread CPU performance versus current-generation Intel mobile processors and significantly better multi-threaded performance, thanks to the increased core / thread counts of the Ryzen 4000 series.


AMD has made some bold performance claims with the Ryzen 4000 H series. For example, in comparison to Intel’s Core i7-9750H, which targets a similar class of notebooks, AMD is claiming roughly 5% better single-thread performance and 46% better multi-threaded performance, with heavy workloads likes Cinebench R20 that will leverage every core / thread. Despite its 45W TDP, the Ryzen 7 4800H even managed to outperform Intel’s Core i7-9700K desktop processor. We won’t dwell much on the performance data AMD has provided here, since it was previously disclosed and we plan to do our own tests soon enough, so stay tuned.


Based on AMD’s claims and what we’ve experienced thus far, however, we are expecting a strong showing from the AMD Ryzen 4000 series mobile processors. AMD seems to have ticked all of the right boxes with these processors. If its partners leverage all of the technologies at their disposal – and it appears many of them will – AMD could shake up the mobile X86 processor market the same way it has in desktops these past few years.