Doesn’t kraken compress the data whilst in transfer?
Not just that.
Kraken VS ZLIB:
According to the official graph by RAD Game Tools, Kraken has 29% higher compression ratio over ZLIB (used in PS4 and other platforms), and does it 3-5x faster (doesn't really concern us as gamers, only good for devs). Both Kraken and ZLIB are lossless compressions, meaning data is kept as it is, like textures, audio, game files, etc. Also another advantage is being 297% (~4x times) faster in decompression, which is very critical for data streaming at least.
Oodle Texture:
Textures in games take a big chunk of the total size. To amplify compression even further, Oodle Texture go 5-15% "near" lossless compression:
Lossless Transform for BC7: Oodle Texture also includes a lossless transform for BC7 blocks called "BC7Prep" that makes them more compressible. BC7Prep takes BC7 blocks that are often very difficult to compress and rearranges their bits, yielding 5-15% smaller files after subsequent compression. BC7Prep does require runtime reversal of the transform, which can be done on the GPU. BC7Prep can be used on existing BC7 encoded blocks, or for additional savings can be used with Oodle Texture RDO in near lossless mode. This allows significant size reduction on textures where maximum quality is necessary.
In short, the PS5 "should" benefit from this headroom advantage to use higher quality assets than other platforms, or be more efficient with its storage for the same assets quality but smaller game sizes. All this while still being able to eliminate LOD's and use that extra space to have a bump on assets quality for the same smaller game size overall.
This is the quote. "Not all games at launch of PS5 will be using Oodle Texture as it's a very new technology, but we expect it to be in the majority of PS5 games in the future. Because of this we expect the average compression ratio and therefore the effective IO speed to be even better than previously estimated."
How Oodle Kraken and Oodle Texture supercharge the IO system of the Sony PS5
The Sony PS5 will have the fastest data loading ever available in a mass market consumer device, and we think it may be even better than yo...
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They also say this in the comments when asked about a comparison to BCPack.
"I don't think there's any public comparison of Kraken and BCPack. If there was one an unofficial one around, beware it might not include the affects of Oodle Texture. Oodle Texture dramatically changes the way textures compress; we believe it should always be used with textures in games. We're big fans of the Xbox Series X. Their approach is slightly different, but we're glad to see they are taking compression seriously. Oodle Texture works great for the Xbox as well, and we are working with a lot of game companies that are using it on Xbox, so consumers should see lots of games with those huge size and speed savings on Xbox as well. It's up to the individual game developers, as it's not been licensed platform-wide at this time. Game developers are also using Oodle Texture and Oodle Kraken for PC games; most multi-platform devs will be using the same Oodle Texture encoding of their textures for all platforms, it's not platform-specific. On the PC you don't have hardware Kraken, so software Kraken is used on the CPU. To keep up with the fastest SSD speeds this requires several cores; luckily high end PC's also have lots of CPU cores! At RAD we've always just tried to make the best compression possible for games. We plan to continue to work with all platforms in the future."