Why is Microsoft so far ahead of Sony with Back Compat?

They had planned BC hardware in during the development of XBO. So it was just a matter of progression towards using that hardware to enable what they needed and just iterating forward. Sony had no way to do that with Cell and this generation. So they only started BC now. Whether they are working on classic PS1 or PS2 titles is unknown.

 

And MS have a ton of software expérience of course...

 

It can't be only one or the other, but I believe MS use some kinds of VMs (virtual machine) "layer" to run BC, and wrappers.

 

This is because Sony comes from the console side and they give lower access to hardware to devs. They need to abstract more the hardware and let a bit of performance if they want to use software for backward compatibility.

 

It is a combination of using weird hardware and allowing developers to use it to the fullest by exposing all of it without abstractions. Especially the Cell processor was incredibly hard for Sony.

Microsoft has used mostly PC hardware and almost always exposed everything through DirectX abstractions alone. This combination has helped them immensely, but they have also put considerable effort into making sure titles were backward compatible when the hardware differences did make this harder (most importantly with the transition from the 360’s special VRAM pool, which probably was their most exotic hardware). So they have long made it a priority as well. They also released the S model with slightly different specs between the one and the X so already have more experience with different hardware configurations to some extent there. Finally, Microsoft has started making it a priority to release their games on PC as well even for their exclusives, so that helps too.

That said, Sony has worked hard on getting their bigger titles to be rewritten to run on PC so that they could finally run on PC hardware for their steaming service PS Now (which initially atoll had to use PS3 hardware - I am not sure if some still do now). Eventually though they have rereleased some of those more important titles as basically rewritten PS4 remasters as well, and from the PS4 onwards they shifted their focus on providing an easier target for multiplatform development, making sure the hardware would be as backward compatible as possible and being able to provide more incremental steps in their hardware transitions (eg PS4 -> PS4 Pro).

They still want their developers to be able to make the most of the hardware though and so they make their hardware as backward compatible as possible. This has very likely also been an important factor for Sony choosing to use 36CUs for the PS5.

As for the rest, we don’t know the BC features of the PS5 in terms of additional features supported so we’ll have to wait and see what kind of improvements they will allow. But it is clear that Microsoft still has the advantage coming into this generation.

 

PSnow still use motherboard with CELL CPU.

 

Because that's a commercial decision more than a technical one.
The question isn't "can we run ps1/2 games on our new hardware" but more "How much will we ear if we invest into an emualtor, and is it worth the cost of relicensing ?"

 

PS1 games only came on CDROM that the PS4 drive physically cannot read. I assume the same for PS5. So they would have to be rereleased on PSN or you play them through PSNow.

These games still work on any PS3 of course.

I don’t know what the situation will be with PS5 there but I’m not sure how many PS1-2 games people would still want to play on that. I would perhaps play a few PS2 games like Buzz if that were possible.

 

MS had the time, money, culture and willpower.

They also had Dave Cutler.

 

If you watched "The Road to PS5" presentation, you'll see Cerny mention that in the past, they included the old console hardware. That's too costly, so going forwards you either design your new hardware to be compatible with the old (PS5 designed to run PS4 code) or you use emulation (PS1 and PS2 emulation on PS4), or various shades in-between with some hardware features to support efficient software emulation.

Alternatively, your software is abstracted away from the hardware so the same executable runs on different hardware. You see this on PC and mobile devices, and more so on something like HTML5 code. The same iOS app will run on old and new iPads because the hardware interprets the software and maps it onto the hardware.

One advantage with software abstraction is scalability. Put a PS1 chip in a PS5 and it'll run PS1 games in their original manner, but run an emulator and you can get high-def upscaling and the like. But if the software isn't expecting that, you are forcing it and may break something.

Abstraction gives you a degree of future-proofing, allowing software to move hardware, at the cost of performance overhead. HTML 5 will run on every device - Android phone, iPad, Windows, console (if it has a good enough browser) - but it won't be efficient enough to allow for a RDR AAA title. And a platform exclusive exploiting the system architecture, poking values into registers at specific clock cycles to eke out a bit more performance, will wow people on what the game is able to achieve but be locked to that hardware and then very hard to carry across.

It seems as time goes on, the value of hitting the hardware decreases and the value in software portability increases. There's a long discussion here from 2011 on the value of BC and a poll on how much lost power through abstraction people would want and a poll on use. I think a lot of opinions have shifted, including my own.

 

My views on BC changed with Sony. Initially I thought it was really important, especially day one to help bridge the gap in games available. However, like Sony suggest from its data, BC was rarely used - it ends up being a ‘nice to have’ feature that minimal people really ‘need’.

Then we come to next gen, suddenly BC is really important because of the ecosystem and many games now are much longer and even infinite. People will want to take their games with them.

MS have had more reasons to ply the BC functionality. They have needed to regain trust after the ‘always online’ etc fiasco and they also wanted to give more VFM as the console lacked in power and exclusives. (IMHO)

So that’s probably why MS are so far ahead and Sony behind, as well as the technical reasons given.

 

Because Sony is complacent.