AMD Zen 4 architecture and Socket AM5: all the details

The  AMD Zen 4 architecture,  the  AM5 socket  and the  B650, B650E, X670 and X670E chipsets  have made possible the  AMD Ryzen 7000  processors that have just arrived on the market definitively. In this article, we are going to review all the  news and technical improvements that have come with this new platform, which will be with us for several years, at least  until 2025,  but it will most likely go further.

Index of contents

  • Zen 4 architecture at 5nm and new I/O die at 6nm
  • AMD AM5 socket, the great novelty
  • Chipsets X670, X670E, B650 y B650E
    • Connectivity X670, X670E
    • Connectivity B650, B650E
  • Conclusions about Zen 4 on socket AM5

Zen 4 architecture at 5nm and new I/O die at 6nm

This AMD Ryzen 7000 processor launches the Zen 4 (Raphael) architecture, AMD’s great leap since Zen 3 arrived almost 2 years ago. As we will see, it is heavily oriented towards improving IPC and energy efficiency, but be careful, we will also see much higher frequencies, support for new hardware features and much more. This is a big jump from Zen 3, and we are going to see it with important data and technical details. AMD has not changed the number of cores in this generation, so all the performance improvements come from the architecture.

As always, a great change that marks all generations is the manufacturing process. Zen 4 is built under the TSMC 5nm process , it is not the most advanced they have (there are already 4nm) but it is an important improvement compared to the 7nm DUV used in the last generation. In the I/O die, the 6nm from TSMC is used, and not the 14nm from GlobalFoundries from Zen 3.

Before we see what’s new in AMD Zen 4, let’s talk about numbers: how do IPC and frequencies improve in this generation? Well, we have 13% more IPC than Zen 3, and we reach up to 5.7GHz turbo frequency. The improvement in IPC is not exaggerated, but it is more than compensated by seeing the massive increase in frequencies: Zen 2 reached 4.7GHz and Zen 3 at 4.9GHz.

And where does this IPC improvement come from? The main contribution is from the front end, which is the first part of the instruction flow, in addition to the load/store part (memory access), and branch prediction. To a lesser extent, from the increase in the L2 cache, which is now 1MB per core (twice as much as before), but this will be much more noticeable in the future, as workloads and space requirements increase. different levels of the memory hierarchy.

In this diagram, we see the architecture of a complete Zen 4 kernel. Let’s now see how AMD describes the various improvements, which extend to all parts of the processor.

From the moment the instructions arrive at the CPU, there are optimizations. Branch prediction, which helps the processor execute actions faster by predicting what the next instruction to execute will be, has been greatly improved. This, along with the other kernel “input” improvements, is what achieves most of the IPC increase.

The execution engine , which is where microinstructions are scheduled and directed to their correct unit of operation, hasn’t changed much since Zen 3. As such, it’s provided the fewest performance improvements. Even so, AMD has increased the queue dedicated to the withdrawal of instructions by 25% to improve this part. Where big improvements do come from is loading/storage, with a 22% larger load queue, reduced cache data port conflicts , and a 50% increase in TLB. forward translation) of data in the L2.

Another very important novelty in Zen 4 is that it finally supports AVX-512 instructions, which are becoming more and more popular in professional software. The most efficient way to implement them, according to AMD without affecting the clock frequency, is to split the 512-bit operation into two 256-bit operations . learning.

Let’s move now to the I/O die of these new Ryzen 7000 processors, where the addition of integrated RDNA 2 graphics stands out, in all the processors in the range, in addition to the improvements in Infinity Fabric, support for DDR5 memories, 28 PCIe 5.0 lines etc All this thinking about the reduction of consumption, precisely for this reason we see it on a 6 nanometer lithography.

Also, a detail that should not go unnoticed: now the processor itself supports USB BIOS Flashback, so motherboard manufacturers will not have the unnecessary responsibility of preparing this feature, they will simply have to add a button to the board and little else. Thus, we ensure that there are no motherboards without this important feature when upgrading to future generations of socket AM5.

As for integrated graphics, we have two RDNA 2 compute units with support for AV1 decoding and H.264 and HEVC (H.265) encoding/decoding. This is a basic iGPU, for normal use. The inclusion of hybrid graphics is appreciated, this means that if we connect our screen to the USB-C port with Dp Alt Mode on the motherboard, we can exchange the dedicated and integrated GPU smoothly to save energy. Same thing with laptops.

AMD AM5 socket, the great novelty

The AMD Ryzen 7000 and Zen 4 processors work under the new AM5 socket, another of the great novelties of this generation. AMD has accustomed us to the great duration of its AM4 socket, which has been with us since 2017 and for which hundreds of processors and motherboards have been launched, from Zen to Zen 3.

However, the arrival of DDR5 RAM makes it mandatory to change the socket, more than 5 years later. AM4 is still very much alive and will remain so, but whoever wants a Zen 4 or future CPU has to go to AM5.

In addition to DDR5, the new socket debuts an LGA design where the pins are on the motherboard, not the CPU. This allows us to have 1718 pins instead of 1331 in the same space, which gives us many advantages in terms of stability of the electrical signal. It is combined with more PCIe lanes, the arrival of PCIe 5.0, more connections, etc.

As we say, the use of LGA clearly improves the power delivery from the motherboard to the processor, and gives us more possibilities to incorporate new functions in the socket, such as better current, power and temperature telemetry to better adjust the boost of the CPU.

Chipsets X670, X670E, B650 y B650E

Of course, the other big component of any platform is its  chipsets,  in this case the initial Ryzen 7000 lineup includes the X670, X670E, B650, and B650E. Let’s explain a little about what they are:

  • As always, the B chipsets  are those that are dedicated to computer motherboards where you do not want to have the maximum connectivity and overclocking capabilities possible, but  something very good  to withstand anything. On X  -series boards  , you’re willing to incur some additional cost in exchange for  maximizing potential overclocking and connectivity.
  • What ‘s new is the  distinction between E and non-E  E boards basically give us  PCIe 5.0 all over the place, essentially we have B650 support only PCIe 4.0 graphics and PCIe 4.0 storage (some will have PCIe 5.0 in storage), and X670 only storage PCIe 5.0. The X670E and B650E boards have PCIe 5.0 in storage and graphics.

Internally, the chipsets bring back, in a way, the classic northbridge and southbridge model. Not exactly like that, but rather they call it “upstream” and “downstream”, but the point is that there are  two chiplets,  one covering some outputs and the other the others. This only happens on  X670 and X670E,  since B650 only has one chip, as usual.

Let us now describe the connectivity of these chipsets. First let’s see what the CPU itself provides us :

  • 4 USB 10Gbps ports
  • 1 puerto USB2
  • 28 PCIe 5.0, 16 for graphics, 8 for NVMe, and 4 for the chipset

Connectivity X670, X670E

  • A elegir: 2 USB 20Gbps, 1  20Gbps + 2 10Gbs, o 4 10 Gbps.
  • 8 USB 10 Gbps
  • 12 USB 480 Mbps
  • 12 PCIe 4.0 lanes for LAN, Wi-Fi, etc.
  • To choose: 8 PCIe 3.0, 6 PCIe 3.0 and 2 SATA, 4 PCIe 3.0 and 4 SATA, 2 PCIe 3.0 and 6 SATA, or 8 SATA.

Connectivity B650, B650E

  • A elegir: 1 USB 20 Gbps o 2 USB 10 Gbps
  • 4 USB 10 Gbps
  • 6 USB 480 Mbps
  • 8 PCIe 4.0 lanes for LAN, WiFi, etc.
  • To choose: 4 PCIe 3.0 lines, 2 PCIe 3.0 lines + 2 SATA, or 4 SATA.

Conclusions about Zen 4 on socket AM5

As we can see, AMD has thoroughly prepared its line of B650E, B650, X670E and X670 motherboards, in addition to its Zen 4 architecture, to prepare us for the new generation. Of course, it will be necessary to see how it develops against its great rival,  Intel,  and its 13th generation of processors.

We recommend reading the best processors on the market.

In any case, what we are seeing here is a platform prepared for  much more than Ryzen 7000,  so it is not trivial. We hope we have clarified some concepts about the new AMD architecture.


by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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