PS5: Pictures of the PS5 CPU “reveal” some differences with AMD Zen 2 Architecture
Tech photographer @FritzchensFritz has shared pictures of the PS5 CPU die a few days ago. According to him, it reveals that the PS5’s CPU is missing parts compared to the AMD Zen 2 architecture it’s based on.
A first quick and dirty die-shot of the PS5 APU (better SWIR image will follow). It looks like some Zen 2 FPU parts are missing. pic.twitter.com/PefXCxc3G1
— Fritzchens Fritz (@FritzchensFritz) February 14, 2021
According to a few other reverse engineers, in particular @Locuza_ on twitter, this indicates that the PS5 APU is a lower end version of the Zen 2 Architecture. Here are the main changes Locuza is making an educated guess on, compared to Zen 2:
- the PS5 APU uses 128 bits Floating Point pipes (same as previous generation’s Zen architecture) instead of the 256 from Zen 2.
- No L3 Cache
My interpretation of the floor plan PS5 floor plan:
1. Bomba surprise that Sony likely cut down the 256-Bit FP pipes to just 128-Bit.
2. No Infinity Cache/L3$, also not on the Xbox Series.
3. Might have the old Render Backend design, need higher res to say for sure.
4. … https://t.co/gwrXI903U8 pic.twitter.com/Vvmm1hGSM8
— Locuza (@Locuza_) February 14, 2021
Keep in mind that some of these are educated guess based on the PS5 die shots, not statements on actual limitations of the PS5 CPU. Now, it’s no surprise that in order to cut costs, consoles would typically use customized CPUs with a few features cut. Whether those are important for games is what matters eventually.
Youtube channel RedGamingTech, which specializes in hardware analysis, state that The PS5 is possibly missing the FFU (Fixed Functions Unit) and the FMADD (Fused Multiply Add) compared to Desktop CPUs and Xbox. But they hypothesize that these are power consuming (not a desirable thing for a gaming console) and possibly not critical for games (if the rest of the architecture is built around this limitation).
Hardware engineer and youtuber NXGamer is a bit more strong in his opinion that these cuts are for the better:
Thanks for sharing, the lack of the FPU extensions for Zen 2 are logical. AVX2 will kill performance, heat, frequency anyway and should not be on the CPU.
Again, as I have said many times, a Console has very different needs and cuts are normal. This is NOT a desktop device.
— Michael T (@N_X_G) February 15, 2021
Multiple people on twitter have also called out some of the limitations on the PS5 APU have been known for a while, and even called out by Sony ahead of the console’s launch:
Cerny even tried to tell them what was really going on in Road to PS5. They refuse to listen. Mark Cerny actually tried to soften the blow in acknowledging that the PS5 would not have EVERY single feature RDNA2 would be introducing. https://t.co/cPViZJk6nc
— SenjutsuSage (@SenninSage) November 2, 2020
Nevertheless, it’s always nice to see some of those CPU die shots 🙂