The new Sony console, unlike Microsoft’s, comes in two different models on the market.
The first model costing 400 dollars does not have a BluRay player and is called Digital Edition, so it can only play games in digital form. The second is the standard PlayStation 5 which has this type of drive and costs an additional $ 100. In case you have PlayStation 4 games in disc format, the standard version is recommended to be able to play the previous generation games that you have in disc format.
The PlayStation 5 SoC
The PlayStation 5 SoC is a chip that integrates all elements of the system into a single processor with the exception of RAM, SSD storage, I / O interfaces, and flash memory controller. This is a custom SoC made by AMD for Sony, so its organization is unique despite the use of parts already seen on PC.
This SoC sits between the Xbox Series S and Xbox Series X in size, as it is smaller than that of Microsoft’s most powerful console, which measures 360mm2, while that of the PS4 is close to 300 mm2. This is partly due to its GPU configuration and some cuts in the CPU cores which we will discuss in this article.
It should be noted that since the launch of the original PlayStation 4, Sony has reduced the total area of its new SoCs with each new iteration. The reason for this we don’t know, but it’s something that gets a lot of attention that we can give to an attempt to get more chips per wafer and therefore more consoles to sell if we look at full glass or due to the fact that Sony economically it has no muscle to hold a more expensive SoC, if we look at empty glass.
The CPU of PlayStation 5
The CPU of the new Sony console like those of Microsoft is based on Zen 2, but this is a slightly shortened version, since AMD at Sony’s request halved all registers for the floating point. The consequence is that you cannot execute AVX-256 instructions in a single instruction cycle, but in at least two instruction cycles. Therefore, its floating point vector capability is closer to Zen than to Zen 2. In any case, one cannot make the mistake of thinking that it is a Zen 1 despite this removed feature.
Another cut in hearts is the removal of the FADD drive. In each Zen 2 kernel, there are two types of units responsible for doing floating point addition, which are FADD and FMAC, the latter being able to perform addition and multiplication in an instruction cycle. In order to add only, the FADD unit takes 3 cycles while FMAC takes 5 clock cycles.
On the rest of the omissions, the rest of the CPU is exactly the same as the Zen 2 of the “Renoir” type of the AMD Ryzen 4000 and both Xbox Series in terms of performance.
PS5 GPU, RDNA 2 customized again
|Basic architecture||AMD RDNA 2 custom|
|Base clock speed||800 MHz (PS4 mod), 911 MHz (PS4 Pro mod)|
|Increase clock speed||2.23 GHz|
|ALU FP32 by CU||64|
|Power in FP32||10.23 TFLOPS|
|Power in FP16||21.46 TFLOPS|
|Power in Int 8||–|
|Texturing rate||321.12 Gtexels / s|
|Filling rate||142.72 GPixels / s|
|L2 cache||4 MB|
|Primitive Mesh / Shaders||And|
|Variable rate shading||No|
|Sampler feedback flow||Proprietary solution|
The PlayStation 5 GPU is almost the same as that of the RX 6700 XT, but with 4 of the 40 compute units idle, Sony unlike the Xbox One to Xbox Series X’s move from 40 to 52, has decided to keep the number d. computing units from PS4 Pro to PS5. Of course, we went from GCN to RDNA 2, or at least RDNA 2 Custom if we take into account what Mark Cerny said in his “Road to PS5” presentation.
The RDNA 2 Custom concept as well as the fact that Sony gave almost no data on certain details of the console’s internal hardware created doubts as to whether the GPU is RDNA 2 or RDNA 1. The origin of this? The PlayStation 5 SoC began to be rumored under the names Ariel, Oberon, and Flute in their various stages of pre-production and SoC design. All the codenames are related to the play A Midsummer Night’s Dream by William Shakespeare and at that time the codename Navi 10 Lite was related to the PlayStation 5 SoC i.e. RDNA 1.
This was Mark Cerny’s presentation where it helped us be clear that the GPU is an RDNA 2, at least they told us about Ray Tracing support. What is the addition of the radius acceleration units, which in RDNA 2 are built into the texture units. However, the addition of RAU appears to be a last minute change in the final hardware. At the end of the day, they just had to change the unity of textures on the original drawing.
Notable absences in the PS5 GPU
The biggest lack of the GPU is Variable Rate Shading, which is a way to save resources when applying the Pixel Shader. The idea of the VRS is to locate lines of instructions that are exactly the same both in the opcode and in the data of it, to unify them into a single calculation instead of repeating them over and over.
To apply this, the RDNA 2 for PC and Xbox had to renew the Render Backend units, which are what we call ROPS in a GPU. Where AMD traditionally separates them into Z-ROPS and Color ROPS. Well, on PS5 they are the same as RDNA and not RDNA 2. The same can be said of the rasterized unit, which is also RDNA. The results? Lack of hardware support for variable rate shading, although it can be done by software.
How fast is the PS5 GPU?
Sony, unlike Microsoft, did not go for a design with more compute units, but they increased the GPU clock speed to 2.23 GHz, but the downside is that this clock speed does not ‘not achieved 100% of the time. The reason is that Sony, unlike Microsoft, has decided to adopt AMD’s SmartShift technology, which means having variable clock speeds in the CPU and GPU.
The idea of SmartShift is that the CPU and GPU share the same energy “environment”, where it is possible that when the CPU is not having a very high workload, it is possible to increase the clock speed. from the GPU and vice versa. Sony did not give the performance profiles for the CPU and GPU, but we do know the maximums for the CPU and GPU.
It should be borne in mind that in SoCs much lower clock speeds are achieved in their components than with them separately, the proximity of the components makes it undesirable to reach maximum clock speeds. With the Smartshift, it is possible to set the GPU to 2.23 GHz at certain times.
The fact that SONY chose this option makes us think that their console’s SoC was already finished with less power and that they didn’t have time to get back to the design table. If they had taken a path with more compute units, it would have delayed the SoC from six months to a year, affecting the launch of the console, which would give Microsoft a year ahead of the market.
RAM memory on PlayStation 5
The PlayStation 5 has 16 GB of GDDR6-type RAM, divided into 8 chips of 2 GB each connected via a 256-bit bus to the SoC where each is GDDR6 14 Gbps, so we are faced with a configuration at 448 GB / s of tape. busy. Sony did not report memory bandwidth data separately like Microsoft, which may be a different or the same approach to memory access.
- Approach # 1: Same as Xbox Series X, but we don’t know which parts of RAM are exclusive to GPU and which are shared between CPU and GPU.
- Approach # 2: CPU and GPU share the same memory space in RAM.
Looking at the console’s SoC, we’re not quite sure which of the two options Sony has done for its new console. The advantage of the Microsoft method is that there is no conflict when accessing the memory by two clients on the same channel, the other method creates an access conflict, because when a memory RAM in a single channel has two clients, the sum of the bandwidths of the two clients are less than the total bandwidth.
The PS5 custom SSD controller
SONY has bet very strongly on the question of storage for the SSD, even if it is not a unique feature in this generation, unlike Microsoft where the controller of its SSD was manufactured by a third party, in PS5 it is a bespoke controller that actually performs two functions:
- As an SSD controller.
- Like the Southbridge of the system.
In the second case, it is linked to the DDR4 memory chip, which is next to the SSD controller, its use? PS5, like its predecessor, has a Southbridge that in standby mode the console runs another operating system that allows it to manage downloads when we have the console in standby mode. Obviously, this operating system needs RAM to run and therefore DDR4.
As Southbridge also integrates a series of input and output interfaces such as SATA controller for UHD BluRay drive.
As for the console’s internal SSD, we have 6 NVMe memory chips on the board located on the front and back of it. Each of the NVMe chips is assigned to 2 of the 12 channels of the flash controller and has a capacity of 128 GB of storage each. SONY talks about 825 GB of storage, but it’s really 768 GB from when they counted from 1000 to 1000 instead of 1024 to 1024. So we are faced with a storage that is 3/4 that of the Xbox Series X, but at a much higher speed.
Unlike the two Xbox series, here we have the four PCI Express 4.0 lanes assigned to the SSD controller, which communicates with the system SoC under a real-speed 5.5 Gb / s bus. Keep in mind that new generation consoles have real-time compression and decompression mechanisms that allow compressed data to be transmitted over the same 5.5 GB bus at a rate of 9 GB / s.
SONY, unlike Microsoft, decided to go with standard M.2 cards for PCs of various sizes, although in the early months of the console’s life, the console and the list of M.2 units with which the console is cannot be updated. compatible is unknown at the time of writing.
The dual PCI Express 4.0 x4 interface on the SSD controller is what attracts the most attention, since the external SSD does not communicate directly with the SoC but with the SSD controller, it means that the flash memory controller that there is has in the M.2 drive if it is faster than the PS5, it will not exceed it in speed. On the other hand, it also allows to launch cheaper M.2 disks for PlayStation 5 without flash controller and SSD.
When it comes to expanding the storage of the console, we are faced with a cheaper option than in the Xbox series since it is possible to use M.2 units for PC, but the consideration comes from the fact that performing the extension is much more complex than in Microsoft consoles.