The PS5 does not have a 400% more powerful decompressor.
When Microsoft says they have a decompression unit that can deliver over 6GB/s, Microsoft, just like Cerny, are likely referring to input data.
This is what Mark Cerny says.
"we hustled and built a custom decompressor into the i/o unit,
one capable of handling over 5GB of kraken format input data a second.
After decompression that typically becomes 8 or 9 gigabtyes, but the unit itself is capable of outputting as much as 22GB/s if data if the data happened to compress particularly well."
Here's the video.
He's talking effective speed
after decompression. Remember when mark cerny shows that 2GB of data being moved into main memory with the SSD operating at 5GB/s calculation? He likely used 5GB/s instead of the rated raw max 5.5GB/s of the PS5 SSD because the decompression unit only accepts just over 5GB of input data. Toss in that being kraken format input data, and the data in that 2GB batch after decompression could represent anywhere from 3.2GB to 3.6GB of data based on the typical compression ratio revealed by Cerny. If the data is just that amazingly well compressed, then the data in that 2GB portion on PS5 could actually turn out to be as high as 8.8GB of data or however far kraken gets pushed. 2GB of data turning out to be 8.8GB of data when decompressed is an example of Kraken with the decompression unit reaching that insane 22GB/s Cerny mentioned, and apparently it's gotten better since. So I admit it's impressive, but by no means is the decompression unit 400% more powerful than what's on Series X.
PS5 has a decompression unit perfectly matched to the performance of its SSD. Series X has a decompression unit whose raw capabilities outstrips the raw speed of the SSD by anywhere from 2.5x or 3x, coincidentally the exact same 2.5x-3x memory efficiency that you get from Sampler Feedback Streaming. Probably irrelevant, but I thought that was interesting.
The effective I/O capabilities of Series X with a fully utilized XVA, meaning with Sampler Feedback Streaming coded into the game, similar reaches well into effective 20GB/s territory and beyond, even without the decompression hardware. Dirt 5 dev says they can move 10GB in 2 seconds on Series X without decompression hardware, that's just raw. If he used SFS, he would accomplish a similar feat in effective performance in just 1.1 seconds, again without the decompression hardware. Sampler Feedback's 2.5x memory efficiency boost would take that 10GB of possible data down to 4GB of data. This feat alone is equivalent to 25GB/s in terms of effective I/O speed. Now toss in actually utilizing the decompression hardware, particularly BCPack for textures. Suddenly that effective 10GB of data, which SFS drops to just 4GB of data is decompressed into RAM in just 0.55 seconds. The overall effective I/O performance in that scenario is now, shockingly, much higher than 25GB/s... People keep sleeping on Series X's I/O capabilities just because the PS5 has a kraken format decompression unit and a faster SSD. It requires more work to implement the Series X's top I/O capabilities than it does on the PS5 side, but when games get it right, it will become a lot more clear how underestimated what Microsoft has done really is. Xbox Velocity Architecture, which is dismissed as a buzzword or a punchline for some today, will not be so in a few years time.
And, yes, I'm aware SFS only affects textures, but textures are the biggest users of game memory anyway, plus Xbox Series X's decompression unit can handle other types of data separate from textures, and has a supported compression format for those other pieces of data
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