Baseless Next Generation Rumors with no Technical Merits [post E3 2019, pre GDC 2020] [XBSX, PS5]

[London Geezer]

I mean I’m not judging at all, if anything I’m sure I’m the weird one. When I think about it, I have PS4 games here that I have not finished or even started (the last two Tomb Raiders for example, and a few more) and surely I could see myself wanting to pick them up and play them one day.

But if BC ends up being a reason for somehow gimped hardware - as some posters seem to think, with the whole 36 CUs debacle - then I’d be a bit mad.

 

[Deleted member 11852]

It's certainly weird that with vastly more games than ever before, people are wanting to play old stuff, like they can't find anything new to play. I guess if one's tastes are more focussed, BC becomes more important to ensure you have those preferred titles and experiences.

For me it's not the lack of new games that compels me to play older games it's because I just thoroughly enjoy some games. I must have replayed Skyrim a half-dozen times (yet have never finished the Dragonborn quest line) and played Fallout 3, New Vegas and Fallout 4 many times. Likewise, I've replayed GTA V a bunch, Resistance Fall of Man and Resistance 2, Infamous 1, 2 and Second Son a ton, the Mass Effect trilogy and Dishonoured 1 and 2 a lot, Horizon Zero Dawn, Uncharted 1-4, The Last of Us and I've replayed The Witcher 3 twice. These are all games where I thoroughly enjoy the games for what they are. All are games that typically were lavished with developer effort.

These are great games, where even if I know what is going to happen (for the linear games) I thoroughly enjoy the core experience or mechanics, e.g. the core combat in HZD and Infamous or driving of Motorstorm. Some games just give more value on replay. Like different choices, skills and endings.

Rather than the need to play something, as I get older I generally to get the urge to play something that scratches some specific itch and I'm happier to replay something that scratches that itch than something new that doesn't.

 

[MrFox]

That weird narrative BC is preventing sony from having more than 36 CU makes absolutely no sense.

If they were staying on GCN and Jaguar then there would be some argument to be made. It's zen2 and rdna, and they disable CUs as back compat fallback mode. The total number of CU is the least of their problems for BC.

 

[BRiT]

But if BC ends up being a reason for somehow gimped hardware

BC in it's perfect final form is PC Gaming, being able to play games from many decades ago. There's no reason it has to be worse, unless your software and OS side is lacking.

 

[Shifty Geezer]

LB means future games being worse due to the need to support BC. And the 'perfect' form of PC is far from perfect - it requires drivers that need constant work to map the games to the hardware correctly. In truth, there is no perfect solution. Windows is the most versatile imperfect solution. Consoles have different needs unless you do like MS and abstract the hardware, but even then it's not perfect and requires per-game treatments.

If you don't give a crap about running old games, you can use brand new hardware with brand new ways of doing things and get the best possible solution for future games. That dream is likely dead with the economics of game development and need to support multiplatforms anyway. If you're supporting multiple platforms (and MS wants to support both Windows and XBox, which is perhaps part of their reason for abstraction and VMs), last gen consoles end up just another platform, as are future consoles, and everything's abstracted.

 

[Deleted member 11852]

That weird narrative BC is preventing sony from having more than 36 CU makes absolutely no sense.

He can certainly speak for himself, but I took LB's post to mean any and all effort focussed on BC is effort that is not directed on something new and exciting.

I think a lot of of 18 CU (PS4) vs 36 (PS4 Pro) vs 36 (speculated PS5) GPU narrative can largely be attributed to things that Mark Cerny did indeed say about the 'butterfly' design of PS4 Pro's GPU layout, which I interpreted as suggesting that keeping things as similar as possible made necessary compatibility an easier thing to achieve. How true that really is, is debatable*

*I do not wish to debate this. ​

 

[Shifty Geezer]

Except that was only pertinent to PS4Pro - a platform of limited appeal which Sony wouldn't want to invest too heavily in. We shouldn't take Cerny's design philosophy for PS4Pro and assume he'd follow the same principles for a whole new PS generation.

 

[MrFox]

The 5700 have the same butterfly design, which proves navi was made by sony for BC (/s), or maybe it was just the most efficient way to route the data paths. The Pro was launched quite early, Cerny said it was a simple solution but that doesn't mean they couldn't do something else with more effort.

Even if it was somewhat related, there is nothing that logically prevents them doing a three panel design, 18, 36, 54 CU which powers down sections the same way the whole point was to switch between 18 and 36 on the Pro.

 

[AlNom]

MUX/DEMUX

Even if it was somewhat related, there is nothing that logically prevents them doing a three panel design

Nothing a 2-bit design couldn't handle. :V

 

[PSman1700]

That weird narrative BC is preventing sony from having more than 36 CU makes absolutely no sense.

Yes that PS5 is going to have 36CU's might not have to do with BC, or just partially.

BC in it's perfect final form is PC Gaming, being able to play games from many decades ago. There's no reason it has to be worse, unless your software and OS side is lacking.

True, and never has PC held back next gen visuals like HL2, Doom 3, Crysis.....

 

[Deleted member 11852]

We shouldn't take Cerny's design philosophy for PS4Pro and assume he'd follow the same principles for a whole new PS generation.

We also shouldn’t assume that PS5 is any different. Assumptions without evidence are bad.

 

[Shifty Geezer]

Indeed. Instead of assumptions, people should make arguments based on evidence and data. What are the arguments for using a 36 CU part? Is it necessary for BC? Is it impossible for RDNA to run console GCN code without a 1:1 CU count match?

 

[Deleted member 11852]

Indeed. Instead of assumptions, people should make arguments based on evidence and data. What are the arguments for using a 36 CU part? Is it necessary for BC? Is it impossible for RDNA to run console GCN code without a 1:1 CU count match?

'Necessary' is a high bar. It implies no other economical solution to achieve the same goal. We do have DF reporting Mark Cerny saying the following, which is messaging Mr Cerny conveyed to other sites.

"First, we doubled the GPU size by essentially placing it next to a mirrored version of itself, sort of like the wings of a butterfly. That gives us an extremely clean way to support the existing 700 titles," Cerny explains, detailing how the Pro switches into its 'base' compatibility mode.

What isn't known, so is an assumption by default, is whether this was the only solution to backwards compatibility. Other statements support the lack of critical abstraction layers in PS4's APIs required for compatibility across incompatible hardware architectures, like 4A Games interviews with Digital Foundry on their experience on porting the Metro games to PS4 and XBO. When the hardware isn't 100% backwards compatibility, 99.99% compatible doesn't cut it.

 

[MrFox]

If we ignore N7P for now , 36CU rdna with 8x zen2 is just a bit smaller than the launch ps4 die (maybe 320mm2?), and we didn't add whatever their solution is for RT and Audio. So it looks like 36 is already barely reaching a reasonable BOM. Also we have to consider the much higher cost of the SSD for this gen ($100 vs $35). It's not a bad target for a single SKU launch.

Even if they launch on N7 because of it's high available volume, they can cost-reduce with N7P maybe a year later. So pushing a higher clock at launch would cost them yield and heatsink material, but only for the first year of production or so. In the long term that choice means a proportionally smaller die for the rest of the generation, quickly absorbing the loss leading first year. The slim revision would later be on a process where 1.8GHz (or more) is low power and good yield instead of a situation like the ps4 slim being 800MHz on 14nm.

 

[Shifty Geezer]

What isn't known, so is an assumption by default, is whether this was the only solution to backwards compatibility.

That's GCN and PS4Pro. That's not a great starting point for discussing BC on RDNA.

For PS5 and RDNA, is the same number of CUs necessary for PS4 emulation?

 

[BRiT]

For PS5 and RDNA, is the same number of CUs necessary for PS4 emulation?

It might be when you don't have software abstraction layer keeping those details away from the games.

 

[PSman1700]

It might be when you don't have software abstraction layer keeping those details away from the games.

With in mind how they kept BC with PS1 on PS2.... hardware solution. PS3 had a build in PS2 basically at launch. PS3 bc on PS4 wasnt there, the Pro was HW style logically. PS5 first time software solution from start?

 

[RDGoodla]

We also shouldn’t assume that PS5 is any different. Assumptions without evidence are bad.

Even if PS5 really needs exactly 36CUs in BC mode, why can’t they design a 56CUs GPU and turn off 20CUs in BC mode?

 

[BRiT]

the Pro was HW style logically. PS5 first time software solution from start?

I could see Sony introducing some abstraction layer for PS5 targeted games making the ability to run on PS6 a little easier. But I don't believe that helps at all in getting PS4 games running on PS5.

 

[Shifty Geezer]

It might be when you don't have software abstraction layer keeping those details away from the games.

Theoretically, that could be masked with some hardware mappings, IMO.

With in mind how they kept BC with PS1 on PS2.... hardware solution. PS3 had a build in PS2 basically at launch. PS3 bc on PS4 wasnt there, the Pro was HW style logically. PS5 first time software solution from start?

All the other platforms had zero hardware similarities with their predecessors and were written to at the hardware level - emulation's impossible. See also XB360 not running XBox games. PS5 and PS4 share effectively the same architectural family and shouldn't, in theory, be being coded at a level low enough to cause problems. XB1 is the same architectural concept as 360 and can emulate okay with enough work on the titles. PS5 should be far closer to PS4 than XB1 is to 360.