Tech babble #1: Consoles will enter the Zen Garden
Updated: Mar 16, 2020
I thought I would make a post to record my tech babbles. I often have these little talks with myself where I discuss, with myself, the current tech and computing hardware and products and stuff. I even disagree with myself on a few points, I can be really unreasonable times you know. Anyway today I am just going to talk a bit about the "Next-Gen" consoles and their hardware and what is important to me going forward with these devices.
The Consoles are going to get Ryzen CPUs
Well, not really. I mean they are using the same cores but they are not branded as Ryzen obviously. I'm just going to say they are getting "Ryzen" cores because it's easier for people to understand and associate the Zen (Zen2, actually, but more on that in a moment) architecture that powers the Ryzen CPU products, and how successful they have been.
So why is this really important? Well, the current generation consoles are a bit crap. I'm sorry Xbox and Play Station fans, it's really true. You can tout how powerful the Xbox One X's GPU is, or how many awesome exclusives the PlayStation 4 and Pro have, but in reality they are using very, very weak hardware for the actual processing bit. I'm talking about the CPU obviously. With PS4 and Xbox One (non X, the Vanilla one). A big shift was made to use the x86-64 instruction set architecture for the console CPUs. This would largely allow them to be easier to program for and allowed for easier custom designs by AMD who are, still today, the only company that can license a reasonably high performance CPU design and GPU design onto one chip. And that was important for the Consoles: A one-chip solution is significantly cheaper and reduces complexity. Margins are very sensitive subject for gaming consoles you know.
Okay, I'm babbling. But this is a babble post so hey ho. Anyway, the consoles are powered using a micro-architecture built on X86-64 ISA (The same top level instruction set used for your desktop, most laptops, and like, almost all computers). This micro-architecture is called 'Jaguar' and I am going to type a bit about it.
Is Jaguar really so bad?
Yes. It's really quite bad. This core was launched in 2014 or thereabouts and was never even originally designed for high-performance applications. This small, low-power optimised core was made for low power mobile devices, tablets, ultra-portables and embedded solutions. It is the same CPU core you could buy in a Sempron 2650 for £25 in 2014. Go figure.
It was chosen because at the time AMD really didn't have any other alternative, the Bulldozer-based cores and their derivatives were just crap, (that's another topic and I prefer to forget those CPUs now that we have Ryzen but hey). Whilst offering higher performance than Jaguar they just simply didn't have the performance / watt to be implemented into the relatively low power console chips, along with much larger die size and transistor requirements.
So Jaguar it was, and well, it kinda worked. I will be fair: the current consoles aren't atrocious but they are honestly held back a lot by this tiny little core. (If you really want to see how tiny this core is, I mean physically, check this die shot. The two groups of little squares on the left at the top and bottom are the dual quad-core CPU clusters. They are Tiny).
Jaguar has, compared to current high-performance X86-64 cores, abysmal performance. The "IPC", like the amount of work it can do in one clock cycle is around half that of current high performance cores, and these CPU cores are clocked in the 2.0-2.5 GHz range in current consoles. PS4, Pro, Xbox One, and X all have 8 of these cores at, or around 2.0 GHz. The newer Xbox uses a slightly customised version of this core that I do not know the full details of but the performance didn't change drastically.
So the current console CPU cores are crap. So what does Zen bring to the consoles?
I spent so much time here telling you how bad the Cores are, I need to explain what this means for games if you are using a console now and are like "I'm okay with this experience". Well, basically, with the Xbox One X having a significantly more powerful GPU than its predecessor, you get higher resolutions, higher graphical fidelity, better effects and such, and higher frame-rates in situations where the GPU would be the limit. But... the other aspects of the game that really massively make a difference: things like the complexity of the world, the A.I, physics, dynamic environments and things like have more NPCs in play at a time, all of that is lagging or not improved at all because the CPU just can't process all that additional information.
The PS5 (I am not sure what the specification of the Xbox Scarlett CPU is, but it likely will be similar) is going to get a 16-thread Zen-based processor using the brand new "Zen 2" architecture. The exact same architecture that features in the Ryzen 3000 series that AMD just showed off. The exact same CPU core that was shown to match or beat the best gaming CPU currently available: the i9-9900K, in games. But does this mean the new console is faster than a PC with a i9-9900K in it?! No duh, the CPU in the consoles will be clocked much lower, around 3.5 GHz to be significantly more efficient.
What this means is the PS5 and new Xbox Scarlett thing are going to have high-end PC gaming-grade hardware in their CPUs. They will have, essentially, a lower clocked highly efficient Ryzen 7 3700X powering them. This is huge.
I'm losing focus so I will try to stay on topic here. These new consoles have more than Twice the performance per clock ("IPC") as the previous console CPUs, and are clocked over 1 GHz (One billion clocks per second!) higher. And have twice as many threads courtesy of Zen's implementation of Simultaneous Multi-Threading. This allows a single CPU Core to effectively work with two logical threads of instructions at the same time, or almost at the same time. It improves multi-threaded performance from negligible improvement to up to 40% depending on the workload. This, broadly speaking is by allowing otherwise idle resources inside the core that thread #0 isn't currently using to be used by the second thread. Modern high performance core designs like Zen are very wide beasts with lots of execution units to keep fed and SMT helps to extract additional parallelism within the core. Intel calls this "HyperThreading".
So going forward what to expect and why are you so excited about a console CPU?
This gives game developers twice as many threads, and potentially up to 3X more CPU power to work with. And I think this is a very conservative estimate. The first games may not take full advantage of this power, but they will in time learn to harness it to make games richer, more detailed, vastly more dynamic. Simulation of Physics, grass, leaves, water, more NPCs, better and highly advanced A.I, more detailed worlds and all this are going to be possible.
In fact, I am so excited about the consoles getting Zen cores that I really don't even care that much if the GPU isn't a huge jump (It is improved, using a Navi-based design with the same RDNA architecture as powering the brand new RX 5700 series). I say that because the Xbox One X GPU is, honestly, not that bad. It's around RX 580 (a bit below GTX 1660 non Ti, or comparable to GTX 1060 6GB if you're on a 10-series) performance and performs perhaps a bit better with direct optimisations possible in a console environment. But you know, those CPUs are going to be Rad.
As for why I'm so excited: sadly, almost all major games are targeted, and developed for, the gaming consoles. Then they are ported to PC with almost no major changes. So that watered down environment and static world nerfed to actually be possible to run on the Literal Potato powering the current consoles, is what we get on our PCs, too. There are exceptions of course, but it's generally the rule.
PC gamers have had this CPU power available in some form or other since only a year after the original PS4 launched (Overclocked i7 5960X, by the way. I'm talking 4.5 GHz+ it's going to be in the same, ish, league as the PS5 CPU. But hey, that was a thousand dollars when it launched. Thanks Intel). So what I am saying is, PC Gamers are in for a treat when developers stretch their legs and write code targeting a high-performance 8 core, 16 thread processor.
That is, unless you bought an i5. :)
Thanks for reading my crap. If you managed to get this far I love you lots <3