Digital Foundry Article Technical Discussion Archive [2015]

Frame pacing issue? Adaptive VSync implemented? Or does the PS4 edition need to be uncapped?

 

I haven't played FC4 to know what its implementation entails, but there are plenty of console games that use parallax mapping, quite a few flavours of the idea actually. It was pretty popular early on in the seventh gen.

 

Yeah Ryse has POM. As well as Crysis on the 360. Metro Redux I believe has paralax mapping as well. Also Strider doesn't have AF on the Ps4 and it is made with the Hex engine.
That would make 3 game engines that apparently have a some problem with AF on the Ps4. I personally think if the problem is software side it would be some sort of comparability issue with the Ps4's SDK or graphics driver. It appears to only occur with 3rd party games. Maybe it could have something to do with games created with DX as the main platform. Something could be getting lost in the conversion.

 

I would put $100 here. I.e. games developed using pure DX11 path and then "optimized" for PS4.

 

So is the ps4 version of dying light 1080p? DF seems unsure....

 

I guess we'll have to wait for the complete analysis, seems DF is just speculating now. It would bother me quite a bit if both versions aren't 1080p, the developer specifically said both would be.

 

They think it's 1080p.

 

Yeah, I had it at 1080P on X1 on my list because of this https://www.facebook.com/DyingLightGame/posts/503677419775309

Obviously I will update that once we get final word.

1536X1080= 1,658,880 pixels, a improvement on 900P (1,440,000). But closer to 900P than it sounds like on first blush, and still a notable pixel deficit to 1080 (2,073,600).

 

Well of course it would be, since the only reason for dropping the resolution is to improve performance. If they only needed to drop the performance by say 5% of the pixels to get desireable performance, then they probably wouldn't have bothered

 

1536X1080 w/ 2x FP16 + depth is pretty close to 32MB

 

I wonder if we can read into the Dying Light results something about platform memory.

Once again, the PS4 drops aniso - presumably because of BW - while the Xbox One has it. The Xbox One will be texturing from main memory, and if AI's figures (above) are representative of the game then the frame could be mostly resident in esram. And that could leave the Xbone with more BW/pixel for texturing and so with a lower and more acceptable hit for applying aniso.

Of course, the frame rate and tearing are pretty bad on the Xbox One so it's hardly as if it's a "win", but it's an interesting curiosity to ponder.

 

Again we have first party titles not suffering similar issues. Perhaps its an engine issue. Chrome engine may still be in development and its possible that the Windows/DX version is further along. Or perhaps its an issue porting from DX to Open GL.

 

There's nothing to compare first party titles to, so you can't know what performance trade-offs they decided to make to use aniso. You can't use them to try and deduce anything about (relative) aniso performance on PS4 (or Xbox One).

I have a very, very hard time believing that some developers haven't figured out how to activate aniso on PS4.

 

PS4 use GNM API not Open GL...

 

The PS4 version of the unfinished swan, originally a PS3 game, doesn't even uses AF when the PS3 game does.

The PS4 version being the same exact game as the PS3 game, just at 1080p with same basics graphics, do you really think they turned off the AF because the PS4 couldn't handle it in such simple game, particularly in such a game with very limited textures load?

And what about 2.5D games like Strider? Even DF thought the lack of AF in this game could only be because of some bug. Do you think the PS4 GPU can't run this game with AF? which only is really activated on some rare oblique textures as it is a 2.5D game.

The fact that after maybe tens of PS4 games lacking AF on PS4 (most of them using Unreal engine 3), no responses from developers or producers, zero patch activating AF on even one game, makes me strongly suspect that they really can't answer us as they must be NDA silenced over the whole ridiculous situation.

It's probably linked to what @psorcerer hinted about DX11 to PS4 conversion.

 

I can't believe it to be a performance issue, honestly. At least not really. The game drops more frames on X1 than on PS4, yet on X1 it has Aniso, which is missing on PS4. Looking back at PC reviews that tested the performance of the different aniso settings, there was virtually no performance penalty besides higher VRAM usage... that is the ones I found (with old ass GPUs from 2010 and older suffered < 10% going from 0x to 8x)

It's just so sad, seeing the well made art being ground into a blurry mess because of it. IQ should be just as high a priority as framerate, if you ask me. Or else, the nice art is wasted.

 

I haven't thought about those games, I'm really only thinking about "current gen" versions where so much emphasis is placed in getting them like for like, in everything other than resolution.

When you put it like that, then yes, there may well be a larger issue. Or it could just be that the PS4 has a particular sensitivity. Or it could be some of both.

Looking a the Xbone for a moment, it's interesting that there's a games where aniso has been chopped like Sniper Elite 2 (it's present on the PS4) where it might be that the 1080p buffer was partially resident in main memory and therefore aniso would be taking precious BW, and a game like Dying Light where there's a smaller buffer and they use it.

People are used to seeing aniso as being effectively almost "free" on PC because the impact is hidden by myriad bottlenecks elsewhere. On consoles that impact may well be very much more evident.

 

Not sure why aniso would result it higher VRAM usage. It's the same textures, just with more samples taken.

It could be for X1 that the aniso is 'cheap' as the bottleneck is shader throughput or ROPs, leaving relatively more main memory BW unused.

I totally agree. If performance is the reason, then they'd have been better dropping resolution and turning on the aniso. Then again, if it'd help the poor frame rate they should have dropped X1 resolution too.

 

Until someone gets ahold of one of the developers of these titles we will never know why they lack AF. It could be reasons we discussed like problems converting DX titles to Ps4 or memory usage. It could even be something we haven't thought of at all. DF should be getting to the bottom of it! After all they interview devs quite often.