Hot Chips 32, XSX Architecture Deep Dive

Sony talked about there geometry engine (mesh shaders) and how RDNA2 is more efficient, has larger cus etc.

Cernys talk had a certain element of misdirection, while everything they said was true what they chose to say and how they said it was quite deliberate. I liked how he described the SSD though I kinda wish ms did something similar, Im curious what the IO hardware is in the seriesX SoC

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Sounds like Ms designed this console the same way they did the X: with a clear performance target and went through a combination of raw power + dedicated hardware to get there.

And you see how all the points of the hardware meshes together really well for that goal.

For example, they had a higher resolution AND framerate target, which will both increase bandwidth consumption. Then thereā€™s raytracing which also consumes a lot. But silicon didnā€™t allowed them to have the required bandwidth. So the memory logical split + VRS allows then to reach 560GB/s plus up to 30% in effective BW gains with VRS.

Same for memory, they again seem to have tested on actual games and realized that on average sampler feedback streaming is an effective 2.5 memory multiplier on average, which was a good bet because memory prices are decaying lower than ssd.

The RT figures also sounds impressive, especially that it sounds like that the performance limitation wonā€™t be due the hardware but rather bandwidth.

Curious about ML too. The performance gains implies they have more hardware than just the int 8/4 acceleration, as that would give performance boost of up to 4x, but they are quoting up to 10x speed up with their hardware. Not to mention calling out image resolution boost as an example given how this also ties with bandwidth I can also imagine it being a big design factor of the console.

It also seems the audio chip is significantly improved from Xbox one which was already able to handle atmos very well.

It all sounds very impressive, canā€™t wait to see what devs are going to do with it.

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I expect, the GPU is 20 Dual CU, with 2 disabled, so 9 DCU available per engine. Sony have got AMD to develop for them a standalone audio processor in the SOC using a CU since these behave well as a DSP.

@ 45:18

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Such a beast of a machine :slight_smile:

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No mention of Series S. What if Series S is the same chip, but those that would have been rejected because of defects? Like with CUs disabled and running at lower frequency?

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I barely understand any of that, but going by what my translators tell me, they absolutely fucking nailed the shit out of this console.

Hopefully devs can utilise it appropriately.

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This is exactly my thought and I think we can safely assume this is the case. There is going to be the Series X and the server blades for XCloud that they are producing these chips for. Anything that ends up not meeting those specs will probably be put into the Series S.

Here is my question. Could MS not even have the specs on the Series completely locked down? What if they are waiting to see what the leftovers from the Series X yields spec out to?

XSX is the only console that has been announced by Microsoft.

On one hand, from what little I could decipher, the Series X is a sexy piece of monstrous machinery. On the other hand, I think Iā€™ll only be able to afford the Series S :sweat_smile:.

The xss will likely have higher demand, using poor yield xsx chips would not produce enough and it would be very hard to control.

Primitive Shaders. Sony never mentioned Mesh Shaders.

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DF said there the same thing?

So do we know if PS5 is using the same fab as XSX? XSX is N7 Enhanced, but do we know of PS5 is plain N7 or N7E like XSX?

Nah they are different. Primitive shaders are older tech than Mesh shaders are.

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Thanks a lot, was searching for something like that.

Iā€™d very much like Digital Foundry or other journalists to directly ask Sony if their platform has VRS hardware and to find out how their ā€˜geometry engineā€™ compares to mesh shaders.

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Interesting that Xbox is planning this transition to high bandwith flash since 2007. Was a long road for our consoles to get ssdā€™s and then being used in that way

Do you think they will answer this time? Because the 1st time DF asked them, they didnā€™t.

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I think if DF pushed them hard enough they would. I can understand DF giving them leeway early on before everything has had a chance to get revealed, but we are getting pretty late in the game here for spec announcements. Do you know what they said to DF when asked the first time? Wasnā€™t sure I saw the actual response.