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|OT| Next-Gen PS5 & XSX |OT| Speculation/Analysis/Leaks Thread

Trueblakjedi

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Mar 30, 2020
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How are they getting to that number? Each GDDR6 chip provides 56 GB/s of bandwidth, right? So if the CPU only needs 1 GB of data, if it's on one chip, then 48 GB/s of CPU access would be able to be provided through one chip, right?

Unless I have that wrong, of course. That said I thought about the possibility if the amount of the slower memory bandwidth can be dynamically accessed, i.e if non-GPU processors like the CPU only need a small slice of the 336 GB/s bandwidth total, the system just gives as much as needed. For example if the CPU only needs 112 GB/s bandwidth, just two of the 2 GB chips are tapped for their bandwidth, while the others can still stay utilized by the GPU, which would include the 1 GB chips that are not given to the slower bandwidth pool.

Figure that should be possible, no reason to lock off six chips for slower bandwidth to something like the GPU on a given set of cycles when there could be many instances where the CPU only needs maybe one or two chips i.e very small amounts of that total slower bandwidth figure. Guess we need more info on how the memory setup works, but I picture that type of dynamic range to the slower pool would help somewhat with contention issues.

And I mean honestly, it's just a bit of an assumed conclusion; I've seen some people elsewhere seemingly think that when the non-GPU processors are accessing the memory, it "locks up" the six 2 GB chips altogether from GPU access regardless of what amount of memory and bandwidth those other processors need. That sounds like a dumb design decision oversight IMHO; would make more sense that the setup is those chips can access up to 336 GB/s bandwidth through the lower bound 1 GB portions of the six 2 GB chips, not that those chips are locked up as some sort of mode setting regardless of the amount needing to be requested.

As far as any upgrades, well if we don't hear anything about delays by sometime in June we can assume the systems are set for release this year. If anything gets announced for delays, it'll be before July IMHO. Just a gut feeling (plus usually that's about the time full production on the systems at mass scale begins I believe, for fall launches).
This description is exactly correct. Thank you for posting this.
 

Trueblakjedi

Neo Member
Mar 30, 2020
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My argument is about GPU's point of view on memory bandwidth. My reason for 168 GB/s is to directly debate against Lady Gaia's 48 GB/s CPU argument.

My argument is based on GDDR6's dual-channel per chip with either 6GB memory range's odd or even channels still allowing the GPU to access 10GB address range while CPU/DSP/File IO/residual GPU is busy with 3.5GB address range.
This is exactly correct. The XSX GPU can always access the lower 1GB of all ten memorychip paths @56GB/S. Always. There is zero contention in that pathway as that uses the 320 Bit bus (32bit x 10 lanes).

The CPU also has access to both the 320Bit bus as well as the 192bit (32 bit x 6 lanes) bus to access the top 1gb of the 6 2GB chips. The CPU can access both busses while the GPU can only see 10GB as thats the only bus its attached too.

OS Audio and other slow memory needs will optimally sit on the 192 bit bus inside of the 6 1Gb chips allocated to slower memory (56Gbps X 6 lanes = 336gbps).
 
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Shmunter

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Aug 25, 2018
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If you REALLY had looked at my post history, you would have known I always wanted both consoles to be the same, I was even ok if MS would have a slight edge(what turned out to be true). It's Xbox fanboys who try to push this narrative that there's this huge gap between SX and PS5, when they just have different approaches to reach their goals.
There is a huge gap. But it’s not in computing power, it’s in the memory subsystem.
 
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Trainsmove

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Jan 6, 2017
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I think MS decided to emphasize it was fixed because they somehow got wind that the PS5 was not fixed. Variable is the standard but it is still very different in the console space where a piece of hardware cannot expect piece upgrades over the next 5-7 years. This is a huge change for the console market and one I welcome. Everybody saying that the XSX is more PC like, I completely disagree. I think the PS5 is the one that is taking a massive step towards PC while also innovating with the SSD in a way even PCs haven't seen yet.
PC'S don't have one pool of memory. One CPU pool that's slower ddr4 and one pool of faster ddr6 .
 

Trueblakjedi

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Mar 30, 2020
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There is a huge gap. But it’s not in computing power, it’s in the memory subsystem.
The memory subsystems gap is vast if you include in the DIrect Storage element where the XSX has direct and instant access 100Gb of game data with no need to stream. Although used before on creator systems with the Radeon Pro SSG, we don't know how that would operate in a game setting.

As far as compute power, if the XSX keeps the same TMU and ROPS count as what we expect for the PS5 (144 and 64 respectively) then the PS5 will actually have the texture and pixel advantage @ 2.23 Ghz. I would not expect MS to hamper their design by increasing their CU count to 52 and not increasing TMU and Rops count accordingly. (I don't think TMUs can be separated from CUs in the AMD architecture can they?)

That said, since we expect that XSX is really a 56 CU part with 4 CU disabled we can look for similarly high then disabled units in the Shaders TMU and ROPS count as well. A comparison of *potential* compute power would look like this:

System GPU Speed CU(base/active) Shaders 64* (base/active) TMUs (base/active) Rops (base/active)

PS5 2.233GHZ 40/36 2560/2304 160/(144*2.233Ghz) = 321.6 Gtexels 64*2.233Ghz = 142.9 Gpixels
XSX (nom) 1.825GHz 56/52 3584/3326 160/(144*1.825Ghz) = 262.8 Gtexels 64*1.825Ghz = 116.8

However I think the TMU and ROP counts dont match the CU in a way that we know AMD designs their cards. The best guess as to the graphics pipeline of XSX GPU comes from here:

XSX (exp) 1.825Ghz 56/52 3584/3328 224/(208*1.825Ghz) = 379 Gtexels 80*1.825ghz = 146 Gpixels

So the jump to 2.233 really DOES help the PS5 close the power gap considerably if the numbers can be effectively maintained in a game scenario.
 
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rnlval

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Jun 26, 2017
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This is exactly correct. The XSX GPU can always access the lower 1GB of all ten memorychip paths @56GB/S. Always. There is zero contention in that pathway as that uses the 320 Bit bus (32bit x 10 lanes).

The CPU also has access to both the 320Bit bus as well as the 192bit (32 bit x 6 lanes) bus to access the top 1gb of the 6 2GB chips. The CPU can access both busses while the GPU can only see 10GB as thats the only bus its attached too.

OS Audio and other slow memory needs will optimally sit on the 192 bit bus inside of the 6 1Gb chips allocated to slower memory (56Gbps X 6 lanes = 336gbps).
Also, each data element has associated address data.

Alternative XSX memory layout









Blue fluid, odd 16bit straws 168 GB/s + 112‬ GB/s two Blue glasses = 280 GB/s with 8GB slice

Green fuild, even 16bit straws 168 GB/s + 112‬ GB/s two Green glass = 280 GB/s with 8GB slice

Total: 560 GB/s
 
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Shmunter

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Aug 25, 2018
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The memory subsystems gap is vast if you include in the DIrect Storage element where the XSX has direct and instant access 100Gb of game data with no need to stream. Although used before on creator systems with the Radeon Pro SSG, we don't know how that would operate in a game setting.

As far as compute power, if the XSX keeps the same TMU and ROPS count as what we expect for the PS5 (144 and 64 respectively) then the PS5 will actually have the texture and pixel advantage @ 2.23 Ghz. I would not expect MS to hamper their design by increasing their CU count to 52 and not increasing TMU and Rops count accordingly. (I don't think TMUs can be separated from CUs in the AMD architecture can they?)

That said, since we expect that XSX is really a 56 CU part with 4 CU disabled we can look for similarly high then disabled units in the Shaders TMU and ROPS count as well. A comparison of *potential* compute power would look like this:

System GPU Speed CU(base/active) Shaders 64* (base/active) TMUs (base/active) Rops (base/active)

PS5 2.233GHZ 40/36 2560/2304 160/(144*2.233Ghz) = 321.6 Gtexels 64*2.233Ghz = 142.9 Gpixels
XSX (nom) 1.825GHz 56/52 3584/3326 160/(144*1.825Ghz) = 262.8 Gtexels 64*1.825Ghz = 116.8

However I think the TMU and ROP counts dont match the CU in a way that we know AMD designs their cards. The best guess as to the graphics pipeline of XSX GPU comes from here:

XSX (exp) 1.825Ghz 56/52 3584/3328 224/(208*1.825Ghz) = 379 Gtexels 80*1.825ghz = 146 Gpixels

So the jump to 2.233 really DOES help the PS5 close the power gap considerably if the numbers can be effectively maintained in a game scenario.
Agreed. Anything is possible and I’m totally comfortable with it.. But what’s clear to me, at these levels it’s a fools errand to be chasing pixel pushing potentials. Neither is lacking and both will deliver. A few extra pixels here or there, do not a change make.

What’s truly new and opens fresh opportunities is access to massive data at unprecedented speeds. Data that was locked behind suboptimal hard drive delivery is no longer a barrier. This is what defines the next gen for development, and the inherent positive results for the end user. It’s pointless to discredit the reality of the matter, but hey it’s entertaining for the most part, very entertaining indeed.
 

Trueblakjedi

Neo Member
Mar 30, 2020
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Also, each data element has associated address data.

Alternative XSX memory layout









Blue fluid, odd 16bit straws 168 GB/s + 112‬ GB/s two Blue glasses = 280 GB/s with 8GB slice

Green fuild, even 16bit straws 168 GB/s + 112‬ GB/s two Green glass = 280 GB/s with 8GB slice

Total: 560 GB/s

I like this diagram. Would it be more accurate to have it so that glasses 5 and 7 are green AND that there is one straw in each glass that can ONLY drink from Green (GPU RAM) fluid?

I don't know the answer but the literature supposes that the GPU can only use 10 of the 20 straws and can only "see" and therefore "drink" from the bottom 1Gb of each glass. Im very interested in this representation and I have never seen it illustrated in this way. Thank you.
 

Trueblakjedi

Neo Member
Mar 30, 2020
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Agreed. Anything is possible and I’m totally comfortable with it.. But what’s clear to me, at these levels it’s a fools errand to be chasing pixel pushing potentials. Neither is lacking and both will deliver. A few extra pixels here or there, do not a change make.

What’s truly new and opens fresh opportunities is access to massive data at unprecedented speeds. Data that was locked behind suboptimal hard drive delivery is no longer a barrier. This is what defines the next gen for development, and the inherent positive results for the end user. It’s pointless to discredit the reality of the matter, but hey it’s entertaining for the most part, very entertaining indeed.
Indeed the last generation that was this architecturally interesting was the PS3/X360. Cell vs EDRAM. I'm learning alot also.

It will be great to see what tradeoffs developers value and how that impacts their visions for their games. First and second party devs are stuck with their hardware and I'm sure they will achieve great things for each system. I'm hoping that 3rd party devs do not chicken out and commission separate teams to maximize the capabilities of each system such that we can do accurate and entertaining head to head comparisons of titles.
 

rnlval

Member
Jun 26, 2017
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I like this diagram. Would it be more accurate to have it so that glasses 5 and 7 are green AND that there is one straw in each glass that can ONLY drink from Green (GPU RAM) fluid?

I don't know the answer but the literature supposes that the GPU can only use 10 of the 20 straws and can only "see" and therefore "drink" from the bottom 1Gb of each glass. Im very interested in this representation and I have never seen it illustrated in this way. Thank you.
Each GDDR6 chip has two 16bit straws which enable full-duplex read/write pattern for GDDR6 chip.

It depends on how MS slices the physical memory address and mapping it to the virtual memory address. Static hardware design is nice for this trickery.
 
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Trueblakjedi

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Mar 30, 2020
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Each GDDR6 chip has two 16bit straws which enable full-duplex read/write pattern for GDDR6 chip.

It depends on how MS slices the physical memory address and mapping it to the virtual memory address. Static hardware design is nice for this trickery.
Yes indeed 32 bit width. My oversight.
 

Insane Metal

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Mar 11, 2006
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The memory subsystems gap is vast if you include in the DIrect Storage element where the XSX has direct and instant access 100Gb of game data with no need to stream. Although used before on creator systems with the Radeon Pro SSG, we don't know how that would operate in a game setting.

As far as compute power, if the XSX keeps the same TMU and ROPS count as what we expect for the PS5 (144 and 64 respectively) then the PS5 will actually have the texture and pixel advantage @ 2.23 Ghz. I would not expect MS to hamper their design by increasing their CU count to 52 and not increasing TMU and Rops count accordingly. (I don't think TMUs can be separated from CUs in the AMD architecture can they?)

That said, since we expect that XSX is really a 56 CU part with 4 CU disabled we can look for similarly high then disabled units in the Shaders TMU and ROPS count as well. A comparison of *potential* compute power would look like this:

System GPU Speed CU(base/active) Shaders 64* (base/active) TMUs (base/active) Rops (base/active)

PS5 2.233GHZ 40/36 2560/2304 160/(144*2.233Ghz) = 321.6 Gtexels 64*2.233Ghz = 142.9 Gpixels
XSX (nom) 1.825GHz 56/52 3584/3326 160/(144*1.825Ghz) = 262.8 Gtexels 64*1.825Ghz = 116.8

However I think the TMU and ROP counts dont match the CU in a way that we know AMD designs their cards. The best guess as to the graphics pipeline of XSX GPU comes from here:

XSX (exp) 1.825Ghz 56/52 3584/3328 224/(208*1.825Ghz) = 379 Gtexels 80*1.825ghz = 146 Gpixels

So the jump to 2.233 really DOES help the PS5 close the power gap considerably if the numbers can be effectively maintained in a game scenario.
Huh. If it's the second case both are really really close, how interesting. PS5 = 86% and 98% of XSX, respectively. That's good enough IMO.
 
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SonGoku

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Aug 16, 2018
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P psorcerer are you a dev? I'd like clarification on the XSX memory configuration
From what i've read online both pools can't be accessed simultaneously, access to either pool must switch on a cycle by cycle basis because the bus is saturated. As a result whenever the slower pool is accessed by the CPU the average bandwidth available to GPU is lower due to wasted cycles

To get around this limitation devs would presumably use the 10GB pool for vram and system ram delegating the extra 3.5GB as a low priority cache (assets textures etc.)
 
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3liteDragon

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Mar 3, 2020
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Engadget writes their own articles.

Your claim was that Microsoft purposely caused confusion by advertising that their clocks are fixed.

I ask one more time, where has Microsoft advertised the Series X clocks as “fixed”


No I’m not playing the dumb game with you.

Post where they advertised it or admit you pulled that from your ass.
For the CPU (timestamped):


For the GPU AGAIN (timestamped):


They mentioned it SEVERAL times like Richard said during their visit to Microsoft HQ, this was posted two days before "The Road to PS5" event was live-streamed on Wednesday, March 18th. Meaning, Microsoft knew beforehand that Sony were going with boost clocks and they wanted to make sure that they let everyone know that their clocks are always LOCKED at the exact same frequency at all times.

Another popular tech YouTuber, Austin Evans also visited Microsoft HQ and posted a video that very same day covering all of the Series X's specs (timestamped).


He also mentions that the CPU runs at "sustained" clock speeds, and he EVEN goes on to say "and that's not some kind of BOOST speed or anything, it can run at 3.8 GHz SUSTAINED, pretty much forever." It's almost as if he was told to say that rather than him choosing to mention it out of nowhere for whatever reason like people don't know that or something.

When he's talking about the GPU's specs (timestamped):


Even on the graphic, it's mentioned that the GPU clock is "sustained" as in like the clock speed is locked and will always remain the same.
 
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Neo_game

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Mar 19, 2020
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A quote from Liabe Brave of era regarding the memory of XSX:


Don't kill me I am just quoting
Yes, I think it is true as I have read other analysis also saying the same thing. So as soon as games start using more than 10gb of ram. BW of both console with will start converging.

BTW who is Liabe Brave ?
 

Vroadstar

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Nov 19, 2013
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If you have two options:

A) you can eat every day for a week.

B) you can eat only five days out of a week, maybe four.

Which is the better option?

Oh and btw, option A had better meals, with better quality meat. But gets to you a little slower each day.

Tough one huh.
A terrible analogy from a bogus insider
 
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