Digital Foundry Article Technical Discussion [2020]

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Yup, and normally this would be an ask for developers - asking them to change the way data is organised, structured and compressed. If Nvidia had rolled this out in isolation I'd be skeptical of it's adoption (speaking as a 2080Ti owner) but with this benefiting nextgen consoles as well. Hopefully devs will make the effort to embrace the paradigm shift.

It is a shame that few existing games will benefit but we don't yet know what performance leaps console games will get on nextgen hardware either. Given their dog slow HDDs I'd expect massive leaps forward but equally I'm not expecting miracles.

I know is too early, but the upgraded Witcher 3 would be a good candidate to beta test DirectStorage on PC.
 
Then why are Nvidia branding this as Nvidia RTX I/O and not just DirectStorage? Perhaps it's just marketing. But some standard needs adhering too for interoperability wit the GPU. Maybe this is the equivalent of Nvidia API extensions for DirectStorage.
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Nvidia probably has Vulkan extensions. Just a guess on my part. So it's DirectStorage compatible, but maybe has some of its own features and works in Vulkan as well.
 
Not even on paper as PS5 best case is 22GB/s.
Isn't that just the maximum speed of the decompression block? Like, it can theoretically write 22GB/s but it can't actually decompress that much per second, so it's ability to write out decompressed data will never be the bottleneck. Or maybe I misunderstood the specs. All of the Sony released specs I've seen simply state the drive speed as 5.5 GB/s raw and 9 GB/s compressed.
 
Isn't that just the maximum speed of the decompression block? Like, it can theoretically write 22GB/s but it can't actually decompress that much per second, so it's ability to write out decompressed data will never be the bottleneck. Or maybe I misunderstood the specs. All of the Sony released specs I've seen simply state the drive speed as 5.5 GB/s raw and 9 GB/s compressed.


It depends on data. Sony said the typical decompressed data rate would be somewhere around 8GB/s. PS5 is capable of that 22GB/s but it requires data that compresses exceptionally well.
 
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It depends on data. Sony said the average decompressed data rate would be somewhere around 8GB/s. PS5 is capable of that 22GB/s but it requires data that compresses exceptionally well.
I get that it's theoretically possible that the decompression block can output 22GB/s, but all of the official verbiage from Sony has been something along the line of "if the data compressed particularly well", but does it? Isn't the ratio of Kraken+RDO something like 3:1 vs uncompressed under ideal conditions? But that combo somehow achieves 33% better results on PS5 somehow? I just don't know how that claim holds water.

I rewatched the Road to PS5 just to get Cerny's quote, and he states that the "custom I/O unit is cable of handling over 5GB of Kracken format input data a second. After decompression that typically becomes 8 or 9 GB but the unit itself is capable of outputting as much as 22 GB a second if the data happened to compress particularly well." That leaves some room for interpretation. It's sort of like me saying "I can punch a hole through concrete, if my fists happen to be made of steel". They aren't. So I can't.

I still think 22 GB/s is the maximum throughput of the I/O block and that will never bottleneck the system, because the compression formats it supports can't compress data that small to achieve that number. To be clear, I don't think this is a bad thing. This is how you design hardware so that it isn't tripping over itself.
 
I rewatched the Road to PS5 just to get Cerny's quote, and he states that the "custom I/O unit is cable of handling over 5GB of Kracken format input data a second. After decompression that typically becomes 8 or 9 GB but the unit itself is capable of outputting as much as 22 GB a second if the data happened to compress particularly well." That leaves some room for interpretation. It's sort of like me saying "I can punch a hole through concrete, if my fists happen to be made of steel". They aren't. So I can't.
To get compression that high, the data must be extremely repetitive or patterned in a very predictable way. Like compressing a table full of largely the same values for instance. That's just unlikely to be the case with most data.
 
I get that it's theoretically possible that the decompression block can output 22GB/s, but all of the official verbiage from Sony has been something along the line of "if the data compressed particularly well", but does it? Isn't the ratio of Kraken+RDO something like 3:1 vs uncompressed under ideal conditions? But that combo somehow achieves 33% better results on PS5 somehow? I just don't know how that claim holds water.

I rewatched the Road to PS5 just to get Cerny's quote, and he states that the "custom I/O unit is cable of handling over 5GB of Kracken format input data a second. After decompression that typically becomes 8 or 9 GB but the unit itself is capable of outputting as much as 22 GB a second if the data happened to compress particularly well." That leaves some room for interpretation. It's sort of like me saying "I can punch a hole through concrete, if my fists happen to be made of steel". They aren't. So I can't.

I still think 22 GB/s is the maximum throughput of the I/O block and that will never bottleneck the system, because the compression formats it supports can't compress data that small to achieve that number. To be clear, I don't think this is a bad thing. This is how you design hardware so that it isn't tripping over itself.

If there is something like mp3's inside game data that would likely get 0 compression and output would be 5.5GB/s. Because the compression is so heavily data dependent sony gave the 8GB/s number which is based on their existing game assets. 22GB/s is real and can happen and ps5 can do that but that kind of data is not your typical game asset.

Any compression number is pretty much uncomparable between each other as long as different parties don't agree on data sets to be used for measurement.
 
If there is something like mp3's inside game data that would likely get 0 compression and output would be 5.5GB/s. Because the compression is so heavily data dependent sony gave the 8GB/s number which is based on their existing game assets. 22GB/s is real and can happen and ps5 can do that but that kind of data is not your typical game asset.

Any compression number is pretty much uncomparable between each other as long as different parties don't agree on data sets to be used for measurement.
Right. I get that. Back in the day we had fun passing around a zip file with a .txt in it labeled as CD keys but it was just the letter "A" repeated enough where this tiny zip file decompressed to 400MB. So maybe i guess in an ideal world we would get something like that. But maybe not, because to achieve 22 GB/s you would either have to saturate the input with enough compressed data It exceeds the ideal compression ratio of Kraken+RDO, which is 3:1. Ideal, not average. To achieve 22 GB/s you would have to decompress 5.5GB/s at 4:1, 33% more data than the idea situation. Or you could decompress at a higher ratio, if the hardware supports that. But we don't know if it does.

To get compression that high, the data must be extremely repetitive or patterned in a very predictable way. Like compressing a table full of largely the same values for instance. That's just unlikely to be the case with most data.
Not only that, you would need that type of data to occupy the totality of the 22 GB of output, or maybe the 5.5 GB of input. That would depend on where the bottleneck resides. We only have Cerny's words on this, the 22 GB is a theoretical output. Based on what? a 4:1 maximum compression ratio that the hardware supports? Or maybe that supports 10:1 but it can only output 22 GB/s because that's the speed it can write to RAM. Or maybe it only supports 3:1 but it can output 22 GB/s, and Cerny was just telling us how fast it could move data to RAM. But at that rate 22 isn't achievable based on the input speed.

I don't take Cerny's statement about the I/O block being able to output 22 GB/s as a statement about ability, more a statement about how they designed the I/O block to not be the bottleneck. It can handle the data that the SSD is going to provide, and not get in the way.
 
Great job Alex. Here's the article...

Crysis Remastered: this is what ray tracing looks like on consoles
An impressive technical feat for Xbox One X and PS4 Pro.

The release of Crysis Remastered draws closer and today we can reveal a technical feature of the console versions that we simply didn't believe possible just a few short months ago - the implementation of real-time ray-traced reflections. In a console game? Really? You can cut to the chase by checking out the embedded video below to see this technology in action on Xbox One X, but the fact is that via clever optimisations, the software-driven RT found in Crytek's Neon Noir demo has been optimised for Microsoft and Sony's enhanced consoles - and it looks very, very impressive.

https://www.eurogamer.net/articles/...stered-your-first-look-at-console-ray-tracing

Tommy McClain
 
The profile top right corner reads DX11 64bit build?

Very good info on this video on ray tracing in general. Great deep dive here.
Great to see the different performance deltas between configurations.

Seeing hybrid ray tracing happening is incredible. Great discussion overall.

Shadows and self shadow is so apparently on the remaster vs the original
 
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Beasts, they've known since March. Interesting compare here.

watching this, felt like I was experiencing an episode of Dark.
perhaps the best Xbox console ever, at least the most console-ish one from MS, it took them almost 20 years but they finally got it
 
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