Next-Generation NVMe SSD and I/O Technology [PC, PS5, XBSX|S]

I believe NV had a demo on the RTX IO nvme storage, i think it was the marble night demo, showing improved loading times, not sure though.

 

Big news from RAD Games:

https://cbloomrants.blogspot.com/2020/09/how-oodle-kraken-and-oodle-texture.html?m=1

They're claiming that Oodle Texture is additive to the previously claimed compression ratio from Sony (something I've previously doubted but looks like I was wrong) resulting in a near 2:1 ratio just like BCPACK.

So this would put the PS5's throughput at close to 11GB/s.

 

Impressive numbers but I still don't think this performance will materialize into anything above and beyond what the Series X/S can do in actual use in videogames.

 

Nice, very competitive with RTX IO 14GB/S then.

 

14.8GB/s with the current fastest drive.

 

You do realize that the 14GB/s number is just an assumption. They are not giving real world example, just like Xbox Velocity architecture assume a 2:1 compression ratio, thus you get double the speed while Sony 8-9GB/s number is their typical number using games. Basically Sony is showing a realistic number while RTX IO and Velocity is showing an ideal number. We still know very little about RTX IO, whether the throughput is limited to 14GB/s or it can scale higher assuming the ratio is higher (probably the later). If it can scale then how far can it scale? is a 4:1 compression ratio will be 28GB/s or there is a limit on that?
Afaik, for Xbox series, the maximum is over 6GB/s (source) so assuming that you put something in it that has 3:1 compression ratio it will not have a 3x multiplier to its speed but around 2.5 because the decompressor in series X will become the bottleneck. For PS5, that limit is 22GB/s (source). For RTX IO? Of course the possibility of RTX IO ended up being faster than PS5 IO even in apple vs apple comparison is high, but right now we still don't know much about it.

Having said all of this, all of them are mainly using compression not to gain speed but to gain space (use less space). Extra speed that come from the compression is just a bonus. You still make Xbox series games expecting you can get at least 2.4GB/s speed from the SSD and not 4.8GB/s since that 4.8GB/s can't be guaranteed. If we take RTX IO number at face value, then game install size targeting RTX IO (and Xbox series) should 50% smaller (compared to uncompressed install) while the same game on PS5 will only be around 30%-ish smaller. Or to look it from a different angle, Xbox series games install size should be around 25% smaller than the PS5 version, at least in theory.
Also if 2.4GB/s is the guaranteed speed for Xbox series, 5.5GB/s for PS5, then what is the guaranteed speed for RTX IO games? I can tell you, it will not be 7GB/s, probably not 3.5GB/s, probably 100MB/s for the near future because nobody will make an RTX IO only games. When SSD (and direct storage) become a requirement, games on RTX IO will still not target 7GB/s. Probably the target for PC games regarding the storage speed in the future is either 600MB/s (because of SATA SSD) or 2GB/s (around Xbox series speed). If you have 7GB/s, everything will load quicker, but for something involving gameplay like PS5 RnC, they will need to make it work on those slower SSD.

 

RTX io is as ’realistic’ as PS5’s, we have only data from the companies behind the products. Youd have to measure each, which isnt done on any. I dont believe NV is lying, or ms or sony, there can be other threads about corruption and lies perhaps.
They all talk ideal situations.

Also, because of Xbox/pc velocity arch integration and teaming up with NV, we probably see games taking advantage of nvme/rtx tech on pc.

 

It's pretty clear that Microsoft is banking on Sampler Feedback Streaming to be the hero here and not just sheer throughout. It's pretty unfair to talk about the PS5's IO solution and then ignore a big part of the Xbox Series X/S's IO solution.

 

Yup. Things like loading times and hitches in in-game streaming will be visible in games like Assassin's Creed Valhalla day one, i.e. in five-to-six weeks! What we'll never know, unless a dev speaks out, is how any of these smart systems impacts performance because there's just no way to measure it outside the dev environment.

 

Does the new Nvidia card perform the decompression on dedicated hardware that's present on the card?

I'm wondering if it'd need to partition some CUDA cores for the decompression, if so then presumably an open world game requiring constant loading would impact performance.

 

This is not correct.

Nvidia have been explicit that 2:1 is the expected typical compression ratio with that resulting in a 2x effective uplift to IO. See here:

I see no reason to doubt this, especially with RAD Gametools recent announcement of the PS5 being able to achieve a similar real world compression ratio. Heck, given that RTXIO uses shaders for decompression, and thus is not necessarily limited to one specific compression routine, it's entirely possible that it can also use Oodle Texture + Kraken just like the PS5.

Again, Nvidia have been explicit that it can:

This we don't know, however we can imply some scenario's. Nvidia have been quoted as saying the performance impact on the GPU of RTX IO is tiny:

Which GPU we don't know. But since we do know that RTX IO will work on all RTX GPU's including Turing, then we can assume a 2060 is sufficient to handle full rate decompression at 14GB/s without crippling game performance, so a 3080 should be capable of 2-3x that.

Compression ratio's are determined by the routine that's used. This is fixed on the consoles because they use hardware decompression blocks. So Microsoft is limited by the compression ratio of BCPACK and Sony is limited by the compression ratio of Kraken (with RDO encoded textures). Both end up around 2:1 and that's unlikely to go any higher. RTX IO appears to use compute shaders so may be able to leverage new, higher compression ratio algorithms in the future if such a thing becomes available but I wouldn't count on it. It's probably a good assumption to make that we'll be at 2:1 for the remainder of this generation unless ML texture upscaling becomes a thing (in which Nvidia would have a massive advantage thanks to the Tensor cores).

So scaling will come from the drive speed itself. Fixed in both consoles and effectively on PC until the launch of PCIe 5.0, at which point we'll probably be onto RTX IO2 anyway!

That's why games scale. Just as cutting edge AAA titles can run on PC graphics hardware much weaker than the consoles while scaling up beyond console graphics at the high end, so too will storage requirements. There are plenty of ways to scale storage requirements, i.e. reduce texture resolution, reduce LOD/draw distance, add in game load screens where required (like Oblivion), pre-cache more on systems with plenty of RAM etc..

There's no reason why games can't take full advantage of the highest speeds available from RTX IO while still scaling all the way down to SATA SSD's and maybe even mechanical HDD's - although I do expect SSD's to become a minimum requirement on many PC games in the near-mid term.

 

No it's in shaders (async). I don't think anything is specifically partitioned off for this, especially given that it scales back to the Turing generation. It's simply down to the developer to allocate whatever portion of the GPU they feel appropriate for their game (although it's unclear how much control they'll have over this, my guess is not much). In either case the performance impact is supposedly very small:

https://www.back2gaming.com/guides/nvidia-rtx-io-in-detail/

 

If it's both ~14GB/s decompression and only a "tiny fraction" of the GPU, then that's very impressive. Unfortunately we don't know what proportion of the GPU is required for 100MB/s compared to 14GB/s.

The IO hardware on the Series X doesn't take up much space on the APU. Interesting to see how it compares to the PS5, if that console is estimated to be twice as fast, then will the IO be twice as large?

I wonder why they decided to have dedicated hardware for decompression if the GPUs are so good at it. At least then a non-open world game could have more shader power when not decompressing. Well, a little bit extra.

 

Except compression ratios in games typically don't even reach 2:1 on average.
Unless they're claiming those compression ratios are already counting with the delta color compression that is natively processed by the GPU, at which point the 14Gbps statement is just dishonest.

Ampere's 14GB/s claim is similar to the PS5's theoretical max of 23GB/s claim. Don't be surprised if the PS5 gets closer to 23GB/s than any Ampere gets to 14GB/s*
* - assuming the graphics card hasn't died of a faulty PCB yet.


Besides, Sony is showing measured throughput numbers backed up by developers, with actual games running on it.
So far nvidia has shown a slide and PR answers to an online FAQ.