PS5 Back-Compat Details Announced

What? How would that be even possible??

I don’t know, that was from the blog :

“Select PS4 titles will see increased loading speeds on the PS5 console”

I think some people are focusing too much on the verbiage of the blog post when most of it is likely just CYA. Even with all of the resources MS have put behind BC, there are still some bugs that get through.

I think it’s more likely that some games will run in PS4 BC mode and not in any Pro or PS5 boosted mode.

I don’t think they are saying that we should expect issues or performance issues on all games as you’re implying.

They have tested thousands of games. So I don’t think that’s the case.

It says errors might occur. If it were a CYA sorta thing, they wouldn’t put those two bullet points front and center at the top of their blogpost.

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I disagree, the fact that they word it as errors “might” occur points to it being a CYA move. Again errors occur in XBO BC games, so them being up front about this shouldn’t really be a cause for concern IMO.

The way Sony has acted this year (smokes and mirrors), it’s not people’s fault to doubt sony.

They started with RDNA2- and VRS and ML stuff is still in limbo for PS5

Then came smartshift- and magically performance is at paek for ‘most of the time’

We believe in generations- oh my, this was just a lie.

And now this ‘verbiage’ is coming as an official statement - so why wouldn’t people be critical about it?

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I’m not saying they are implying all games will have issues, but I’m expecting a sizeable portion given how they are handling everything, including not show the games running on ps5 during their presser (Despite making a point about how everything else was running on ps5).

Games requiring updates for bc, and not for enabling boost mode, is a bit weird also.

But I just don’t think Sony earned the benefit of doubt regarding BC.

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The way in which Cerny outlined BC, is that the PS5 adjusts its clockspeed and the number of CUs used to turn itself into a PS4 and PS4 Pro. So if that is the case these games do not benefit from faster clock speeds at all.

The Pro had a Boost Mode that some PS4 games supported and they will see a boost that comes from a higher CU count, sure, but everything has been so vague that I can’t say for certain whether games will look that much better. They did mention unlocked resolution and framerate modes getting better, so you’d think something is happening, but it certainly sounds like these games aren’t fully utilizing the PS5 hardware as they are running in PS4 and PS4Pro modes.

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That’s not what I took away from what Cerny was saying. To my understanding, PS5 will run BC games at boosted frequencies, and only fall back to one of the legacy modes in cases where that proves to be problematic. We’ll see soon enough.

Yes this is how it is supposed to work on PS5. It is called clock spoofing and the patent that I saw a long while ago (while searching for patents as a pass time lol) was deposited by Cerny himself.

Everything is here inside.

Here is the proof:

Backward compatibility through use of spoof clock and fine grain frequency control

“An application runs at a first operating frequency if the application is designed for a current version of a system and runs at a second operating frequency if the application is designed for a prior version of the system that operates at a lower frequency than the first operating frequency. The second operating frequency may be higher than the operating frequency of the prior version of the system to account for differences in latency, throughput or other processing characteristics between the two systems. Software readable cycle counters are based on a spoof clock running at the operating frequency of the prior version of the system, rather than the true operating frequency. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.”

(…)

"Several methods may be used for running applications created for the less powerful console on the more powerful console. In one example, the more powerful console may be set to run at the frequency of the original console. At this frequency setting, the operation of the more powerful console will vary based on the specific processing being performed at any instant of time, and may be slower or faster than the less powerful console due to the latency (and other) characteristics of that specific processing being performed. When the operation of the more powerful console is slower than the original console, many errors in the application may arise due to the inability to meet real time deadlines imposed by display timing, audio streamout or the like.

In another example, the more powerful console may be set to run at a much higher frequency than the original console. Speed of operation will vary based on the specifics of the processing being performed, but it will be consistently higher than on the original console and thus real time deadlines can be met successfully. However, many errors in the application may arise due to the untested consequences of such high speed operation. For example, in a producer-consumer model, if the consumer of data operates at higher speed than originally anticipated, it may attempt to access data before the data producer makes it available, and although synchronization mechanisms may exist they are unlikely to be tested under such conditions on the original console. Alternatively, if the producer of the data operates at higher speed than originally anticipated, it may overwrite data still being used by the data consumer."

More in the link of course.

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Sonys blog says “select PS4 games will benefit from the PS5 console’s Game Boost”. How many games these selection consists of is your best guess.

I mean, it is a support/help page. So I guess that context is important here. Still, it would be a real shame if the bare minimum can’t even match the native PS4 environment. They built their SoC around achieving that, after all.

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Considering how MS still doesn’t have every game available for BC yet, it shouldn’t be surprising to see Sony in the same boat. Both companies seem to still be in the final stages of their BC development, so I wouldn’t read too much into what Sony has or has not shown yet.

Not sure what you mean by games requiring an update for BC but again, I wouldn’t read too much into the boost mode comments. They said the same thing about boost mode on the PS4 Pro and yet it worked on almost every title that could take advantage of it.

Giving them the benefit of the doubt is one thing, but you’re implying the worst case scenario with how BC will turn out.

I’d be surprised to see any game run worse than they do on the PS4. The worst I seeing it run is a game with PS4 Pro mode, run in standard PS4 mode on the PS5 because of some unique way the PS4 Pro was utilized. Unfortunately we don’t know enough to really predict how things will turn out but I don’t see any cause for alarm.

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I mean the disclaimer that games might have extra updates for running on ps5.

(And the previous disclaimer found in the store code that they would be issuing updates to improve compatibility and minimize the issues so folks should continue check if the game was updated).

Not sure what you mean that not every game is BC on the Xbox side. Ms has been pretty clear that everything that works on xbone works on SX|S save some odd licensing issue. They in fact have updated every single game on the store with SX|S compatibility even.

And yeah, I’m assuming the worst. They haven’t even showed a single second of a BC running on PS5 yet.

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That all could be pointing to PS5 BC enhancements. No reason to assume that indicates games will run poorly.

And what I mean about BC on the xbox side is that not every game is currently available on the Series X for people with preview units. This means, they are still in the final stages of their BC development and it would not be surprising for Sony to be in a similar step.

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Not concern, nor alarm is on offer here. Not from me, at least. Moreso wanting to know exactly what customers can expect. PS4 games running on PS4/Pro hardware don’t have errors or unexpected behavior, so evidently some titles do run below what you are describing. Otherwise they would not need the disclaimer. I’d love to see Sony do what MS did wrt giving outlets a bunch of titles to test out so we can get a better idea what to expect.

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Probably just boilerplate CYA language. I would expect nearly all games to have improved performance and loading times, but there could be some oddities.

I’d love to see that too. Unfortunately, I don’t see us getting a closer look at BC until the system launches.

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I’m hoping they will let DF get a hands on for at least the Boosted titles.

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