Digital Foundry Article Technical Discussion [2020]

[chris1515]

For the record, I think Sony really dropped the ball on these two. The first should be really simple to implement - downscale output from 4K mode - and the second is really just compliance with the HDMI 2.1 spec.
Here's hoping they'll solve both ASAP, though the fact that these aren't coming on day one is rather inexcusable IMHO.



Will do!
It's just so hard to avoid vindication from all the targeted harassment of late 2019.. but I promise to avoid it from now on.


Secret Sauce® - 2020 edition.
j/k



I guess we should start killing off the veracity of the rumors repeated ad nauseum by that capcom leaks guy, about the SeriesX version running so well and the PS5 running so badly.

Yes I just begin to read the DF Face off and they talk about the SDK problem rumor at the beginning of the article.

EDIT:
https://medium.com/@mattphillips/te...-of-comparing-videogame-consoles-4207d3216523

This is the reason Matt Phillips write this article, he was knowing.

 

[Jay]

Performance of XSX, MS has an API problem, the GDK is not finish and it has an impact. We will see if this is true but I heard multiples titles runs better on PS5 because of that.

EDIT: Or they need to come back to XDK but something need to change there is some performance lost because of the software. This is a better situation than if it was a hardware problem.

From my view, UWP failed that was supposed to be the universal development platform.
So they moved to GDK.

We've heard for a while that XSX development was problematic, and from the snippets of the GDK documents that has been talked about it's obvious and easy to see why.

They won't go back to the XDK, just means their tools and profilers etc aren't up to scratch at the moment. Probably also lots of unoptimsed api's also.

Also, I was under the impression DMC5:SE wouldn't have RT on Xbox or PC at release, so this was a bit of a surprise too.

I assumed it was marketing deal, but obviously not.

Theres a lot to be said for being lead platform especially when timelines are compressed.
So I'm especially surprised XSX even got RT.

 

[Karamazov]

"PS+ members, download now your free exclusive RT mode DLC !"

 

[novcze]

DF mentioned that there is no way how to limit output from the PS5 to 60Hz if you have 120Hz capable device? And if you switch to 1080p there is no performance benefit because system does downsample from whatever internal resolution is? Like really?

Regarding ALLM, VRR and resolution support, I think it's more that it's a surprise its not in it from the start than it not getting support at all. May even be there on day 1 patch.

I understand VRR and 1440p demand, but ALLM is like automatic switch to TV game mode, which doesn't disable all image processing and usually chroma subsampling happens. PC mode for me is ideal, 4:4:4 is retained, you see exactly what your PC/console is outputting and you still have control over white point and gamma.

 

[pjbliverpool]

Could this not simply be down to the fact that the XSX only has 82% the raw fill rate and geometry throughput of the PS5? Perhaps at high framerates they take over from the shaders and memory bandwidth as the primary bottleneck?

And perhaps this game is generally quite fill rate and/or geometry bound which is minimizing the performance difference at the higher quality settings.

It's likely that future games with other perhaps more shader heavy workloads will favour XSX more.

 

[Jay]

New DF mentioned that there is no way how to limit output from the PS5 to 60Hz if you have 120Hz capable device? And if you switch to 1080p there is no performance benefit because system does downsample from whatever internal resolution is? Like really?

Just watched it.
Unless I'm mistaken it's even worse than that.
It's running in 120fps mode which isn't consistent so feels really bad.
The inconsistencies are so wide on XSX even VRR only slightly helps.
But being able to lock it on XSX makes the game payable on it and currently the better place to play.

Be interesting when it starts getting patched, but it'll be a shame if they lockdown fps wothout being able to unlock it for benchmarking, as we vould see the engine improvements made etc.

 

[Silent_Buddha]

Also, I was under the impression DMC5:SE wouldn't have RT on Xbox or PC at release, so this was a bit of a surprise too.

I imagine this could be due to the seemingly semi-rushed nature of the MS GDK. If Capcom are using the GDK to deploy the updated DMC5, then it could be that they didn't think the GDK would be ready in time to allow them to put RT into the XBS/PC version in time for launch.

So, it's possible that the RT in the XBS/PC version of the game was rushed once the GDK was at a point where they could add it in.

Regards,
SB

 

[Jay]

Could this not simply be down to the fact that the XSX only has 82% the raw fill rate and geometry throughput of the PS5? Perhaps at high framerates they take over from the shaders and memory bandwidth as the primary bottleneck?

And perhaps this game is generally quite fill rate and/or geometry bound which is minimizing the performance difference at the higher quality settings.

It's likely that future games with other perhaps more shader heavy workloads will favour XSX more.

I currently think that high framerate mode is pushing the api's harder, so any inefficiencies are magnified. Hence the much wider swings and drops.

 

[snc]

https://twitter.com/x/status/1326580646362243076

 

[iroboto]

I didn't want to log back into this forum, I actually stepped away knowing this would happen, honestly getting tired of the back and forth reading from both sides. But I came back to respond to this; as much as you may disagree with someone, we shouldn't attack the posters here directly. We attack the argument. I don't agree with his argument, and he is far from vindicated. I disagree with put so much backing behind a single data point, on a title specifically designed around last generation, with some added RT and unlocked features and all it a day. They developed DMC 5 around last gen + mid gen. An optimized title for 36CU (ps4pro/ps5) and a faster front end than X1X, gets a sudden boost of 2.5x just on clockrate alone and whatever additional enhancements obtained from RDNA2, it's the same code but nearly 3x faster.

Ignoring SDK issues here, last gen titles would have been built heavily around traditional rasterization pipe with compute shaders to increase complexity. With PS5 being significantly faster in the front end, the only moments Xbox may be able to catch up is when there are shaders that are ALU bound. Obviously there are sdk issues, Xbox is dropping to terrible frame rates when nothing is happening is not normal behaviour we would come to expect. So we know there are problems.

I would say, expect PS5 to jump off the line here for the next 6 months. Cross gen titles will benefit it significantly where the games are designed around a traditional FF setup and the complexity of compute shaders being relatively less than what we expect as titles mature. But over time, as more titles release they should fall into line for expectations. Hardware never changes, so it's really about the software coming to grips. It's a long generation, the first few titles are never going to be indicative of the majority of performance later down the line.

I spoke with Matt H on the subject of cache hits and clock rates. The key to their success will be ultimately to ensure the data is in those caches so that the GPU isn't sitting idle waiting for memory to come. I don't know if he spoke on record about it, but that was our convo on discord. But what you're really talking about in this case, is that if you had 100% cache hit rate, you're getting closer to hitting that maximum throughput of 10.23TF.

Whereas if you're running slower clocks, the penalization from sitting idle is less, so when the data arrives you swing it across all the CUs and you do a lot more work with fewer clock cycles, but each clock cycle is significantly longer. So there's definitely going to be challenges in coding here given how they both approach obtaining power is dramatically different. But as Matt writes, sitting idle waiting for memory is going to hurt achieving 120fps.

I'm out again. Too many titles to play and looking forward to playing Demons Souls finally.

 

[Globalisateur]

John said that with that comparison there was no performance winner overall. That should be a big surprise on its own. Apparently a narrow and fast design has its own advantages.

Could this not simply be down to the fact that the XSX only has 82% the raw fill rate and geometry throughput of the PS5? Perhaps at high framerates they take over from the shaders and memory bandwidth as the primary bottleneck?

And perhaps this game is generally quite fill rate and/or geometry bound which is minimizing the performance difference at the higher quality settings.

It's likely that future games with other perhaps more shader heavy workloads will favour XSX more.

Yes, I agree, but what about the RT quality mode? (4K reconstructed, both around or under 60fps). This is where the difference is negligible between both machines and this is where XSX should have a noticeable edge (17% more tflops and 25% more bandwidth).

 

[Silent_Buddha]

https://twitter.com/x/status/1326580646362243076

Ooof, that's pretty rough. But I'd hesitate to make any definitive statements as to the hardware design choices at launch. Obviously one platform has a more mature development environment than the other so it's hard to say whether things that are sub-optimal are due to hardware, maturity of development environment, or even how much time was spend optimizing for titles that were obviously rushed in order to make it in time for the consoles launch.

For example, the first year of PS3 compared to the later in the generation when the development environment improved significantly.

Regards,
SB

 

[chris1515]

 

[Arwin]

It will never be like the PS3 I think though as something as extreme as the completely new Cell processor with its seven SPEs with its local memory and combined with the split memory pools etc (and even the 360 had that VDRAM) was especially back then a huge paradigm shift, which led to new workload approaches in gaming that the current generation of consoles are still benefitting from today.

Compared to that these consoles are a breeze to develop for and will reach much of their potential sooner.

 

[Deleted member 13524]

Performance of XSX, MS has an API problem, the GDK is not finish and it has an impact. We will see if this is true but I heard multiples titles runs better on PS5 because of that.

Are we sure this API problem on the SeriesX has an impact on performance, and not just development time/cost?

And even if the dev teams had more time to optimize for the SeriesX to get higher performance, why should we assume they wouldn't also get more performance out of the PS5 if given more time too, like Matt Hargett is suggesting in this last tweet?

I spoke with Matt H on the subject of cache hits and clock rates. The key to their success will be ultimately to ensure the data is in those caches so that the GPU isn't sitting idle waiting for memory to come. I don't know if he spoke on record about it, but that was our convo on discord. But what you're really talking about in this case, is that if you had 100% cache hit rate, you're getting closer to hitting that maximum throughput of 10.23TF.

Soooo... is there more LLC on the PS5 or not? Did he spill the beans?

 

[Deleted member 11852]

I'm out again. Too many titles to play and looking forward to playing Demons Souls finally.

Because this thread was not punishment enough?

 

[iroboto]

Soooo... is there more LLC on the PS5 or not? Did he spill the beans?

In a general statement.
If your power is derived purely by high clock rate, the more cache the better. You lose too much going back to main memory.

Cache helps everything in this way, but he made it apparent that hitting main memory a lot will hurt ps5 very badly. Whatever that means is unsure if he is hinting or not.

 

[Jay]

Are we sure this API problem on the SeriesX has an impact on performance, and not just development time/cost?

And even if the dev teams had more time to optimize for the SeriesX to get higher performance, why should we assume they wouldn't also get more performance out of the PS5 if given more time too, like Matt Hargett is suggesting in this last tweet?

Yea, it can have a drastic performance impact.
It's not just api's either its things like profiling tools.

Wether its having a huge affect, none of us knows right now. But it fits with a lot of what we know.

I'm also not saying that its going to suddenly jump to 30% advantage or anything, just that it seems to have issues at the moment.

 

[Shortbread]

You guy's should take up your personal issues with each other via PM. This is becoming muddy and unnecessary.

 

[BRiT]

Would you kindly, everyone, move on to the rather enjoyable technical videos and articles...

Failure to do so will result in having more time away from the forums to enjoy the awesome next-gen consoles from Sony and Microsoft, one or the other or best of all both!