Machine GPU vs PS5 GPU // a deductive breakdown (& a mental one too)
Hello everyone, welcome to my TED Talk™ about "Why the PS5 GPU isn't better than the Machine GPU by any significant metric"
I have :
- time to kill
- too much love for the game
- severe autism
- fallen down a rabbit hole
- been pissed off by the people claiming the PS5 is better than the Machine in performance
- forgotten to take my meds
Pick any/several of those, I don't care.
Get a snack, we're about to embark in on a marvelous journey of technical specs & numbers aplenty.
Machine GPU only has 8GB VRAM, PS5 has 16!
- PS5 does not have 16GB VRAM, it has 16GB of unified RAM that is divided between system RAM & VRAM, typically into an 8/8 division, can be reallocated up to a 4/12 (practically never happens, most studios port their games over to PC where 60~65% of the userbase has 8GB GPUs, makes no sense to create extra work and touch up the VRAM allocation on the PS5 if it's gonna work all the same anyway).
- 1080p gaming in nearly all games rarely even approaches 8GB VRAM unless texture/effects are set to the higher end of the quality setting scale, which is NEVER the case on the PS5.
- Here's a chart of widely played games with intense graphics that hit above 8GB VRAM when set to 1440p high/ultra. (Notice how most of them don't even go over the threshold by a lot.)
Valve claims 4K@60FPS, bullshit!
- Valve claims 4K@60FPS with FSR, AMD's upscaling method.
- Consoles run games upscaled, this is guaranteed to almost always be the case for 1440p & 4K, some games run 1080p upscaled.
- AMD finally announced FSR4.1 support for RDNA3 & RDNA2 GPUs (respectively planned for July & "2027") so the PS5 doesn't have the argument of having better upscaling quality with PSSR over FSR3/3.1 anymore.
PS5 GPU is equivalent to an RX6700, far beyond the specs of the Machine GPU!
- the PS5 GPU has an RDNA2 GPU packing 36 compute units, which is also what makes up an RX 6700
- Except the PS5 in its entirety uses 200~220W, which includes the CPU (x8 Zen2 cores, 8MB cache, equivalent to a 4700G, which should draw 65W on its own, let's cut that in half to 35W, aka the 4700GE, for argument's sake), SSD & RAM (let's say equivalent to 10W for both combined), all the I/O (wifi, ethernet, 2.4G dualsense, the HDMI port, give it 10W for the whole thing), we can probably ignore the cooling fan and the roughly 10% inefficiency expected from the PSU.
- We then have a GPU that "only" gets ~140W at peak, is driven by a downpowered CPU, has to share a 256-bit bus from 14Gbps memory modules with the CPU, only has 4MB of L2 cache & has to share 8MB of L3 cache with the CPU
- the RX 6700 gets a full 175W, has its own VRAM pool of 10GB of 16Gbps modules through its own 128-bit bus on top of the the PCIe4x16 interface and we can assume that most of the benchmarked scores we can find online are never done with a CPU that has the limitations of the PS5's CPU (i.e. a full 65W TDP or more & 4 times as much cache found in desktop CPUs)
If you followed me so far, I think it's safe to say equaling the PS5's GPU to an RX 6700 is NOT an accurate metric.
- There have been many videos comparing the PS5 to a PC build of some sort, trying to emulate its performance, mostly in cost-based build challenges :
- Performance & Quality comparison with an A770 (Notes : this is a 2y/o video, Intel driver's were inconsistent, had considerable CPU overhead & this was done on Windows, also I know this comes with 16GB VRAM but this is a focus on the performance level, this will come up later)
- Performance & Quality comparison with an RX 6600 (Notes : this is a 6months old video, running SteamOS; here's their logic behind the pick of the GPU, this will also come up later)
- You can look up more performance comparison on your own but I consider that it is safe to say, in sheer performance, the PS5 lands between those two landmarks that we can place on a performance scale.
Oh look, a performance scale!
The two GPUs mentioned above span a 17% performance amplitude, that's a decent window for the Machine to aim into
What does the Machine's GPU pack:
- RDNA3 GPU made up of 28CU, pushing 110W @ 2.45GHz (specs sheet says "max sustained" clock, I'll presume this is what the Boost clock is; VRAM bandwidth undeterminate, I presume it's the same 18Gbps GDDR6 all RDNA3 GPUs got)
- Closest known model? the RX 7600M : same CU count, 90W TDP, boost @ 2.41GHz, PCIe4x16 interface, cooled by laptop-grade thermal blocks, performance about equal to a desktop RTX 2070
Oh, how convenient, that's juuust ahead of the RX 6600 from earlier!
- Difference to the profit of the Machine GPU : +20W TDP, +40MHz boost clock, cooled by a huge fucking block of an air cooler (will likely sustain boost clocks a hell of a lot better & longer than the 7600M in laptops)
- Coincidentally, the XT variant has interesting specs too : 32CUs, 120W TDP, boost @ 2.47GHz, so that means the Machine GPU CANNOT out perform this particular model, since it has physically more compute unites & a teeny tiny little bit more juice & clocks as well
- Why does the 7600M XT matter? Well, let's look at the chart :
Just 2% ahead of the A770 from the first PS5 comparison video? AND equal to the 2070 SUPER?? Now that's very practical!
Let's compile all this data:
We can deduce it's equal or very close to equal to PS5 GPU performance
Extra considerations:
- Machine's CPU is significantly better, feeding the GPU more data more consistently
- PS5's OS is BSD-based, not Linux-based (which makes sense for various licensing reasons from Sony's position)
- Recently released PS5 Linux project allowed for Linux gaming testing on PS5; in all tests, Linux ran equal or a liiitle bit better
The PS5 Linux project at this time can't allocate more than 6GB of the VRAM, and yet still equals or edges ahead of the PS5 in the same games at same resolution & quality.
It runs games which are made for Windows, running through the Proton compatibility layer, whereas the PS5 gets its own custom-optimized editions, just for it. Imagine if it was Linux-optimized, before even thinking about the hardware optimization.
- This project was only operational recently, which mean most of this isn't fully fleshed out, dynamic allocation maxes out at 6GB VRAM, it doesn't boost properly/can't be overclocked, etc...
- I think we can safely assume there's overhead that can be reduced, putting Linux ahead of the PS5's OS down the line because PS5 is basically entirely dependent on Sony software engineering to improve performance; Machine benefits from Linux community (including Valve) to ever improve & optimize software
- Example #1 : MESA 26.0 update packs decent improvements to AMD GPUs RT performance
- Ex #2 : dmemcg Linux kernel patch evicts non-game apps out of VRAM when game requires more space (look up benchmarks before/after patch, this greatly helps 8GB -or less- GPUs)
- Ex #3 : Proton compat layer gets ever better, no need to wait for a Linux port of a Windows game the same way console games have to get ported to PC
- Ex #4 : Microsoft wants Windows to be as good as SteamOS in gaming (this is not a joke, they realized Linux was getting better at running Windows games than Windows LMAO)
But the PS5 is older, shouldn't the Machine be better?
The PS5 has a downpowered, low to mid-end desktop GPU only one generation older than the entry-level, juiced up, mobile GPU of the Machine that only has the 55W RX7400 below it in the RDNA3 series, the gap is, as described by all of the above, non-existent.
I'll bring your attention over to NvidAI, where the RTX5050 is the FIRST entry-level GPU to beat the GTX1080Ti.
It took them 5 generations over the span of a decade to finally achieve that (and it still has more VRAM than the 5050 LMAO).
Why didn't you compare it with the PS5 Pro since it's gonna be closer in price?
- it was not a cost-based comparison
- people who know nothing about hardware were pissing me off saying that the base PS5 was more powerful
- PS5s are subsidized, I wonder what would be the real price if it wasn't & how much consideration would buyers have knowing the Machine can do all the PC-stuff (i.e. running non-game software, having the freedom of choosing what system you want to install, etc...) that consoles can't
Conclusion:
The Steam Machine GPU is equal in performance to the PS5 GPU & can be expected to be supported longer & better than PS5.
If after all that you're still not convinced, then I don't know what to tell you.
go buy a PS5 if you think it's so much better than the Machine, I guess