Why is the Sony PlayStation PS3 so hard to emulate ? | MVG

sony has recently announced their backward compatibility for the playstation 5 with a commitment to support what they label an overwhelming majority of playstation 4 games over 4 000 titles and in some instances game specific enhancements will be applied this is good news in recent times sony has hesitated to support backward compatibility with razor sharp focus firmly in the future but this wasn't always true in fact historically sony has done a good job preserving its library and bringing it forward the sony playstation 2 would contain ps1 hardware on its motherboard for near-perfect backward compatibility early models of the playstation 3 would do the same with playstation 2 hardware only later sacrificing the hardware in favor of software emulation but this would all change with the playstation 4. while still able to support ps1 and some ps2 games via emulation playstation 3 was nowhere to be found this was especially confusing to its customers who are wanting to bring their existing games forward yet were unable to sony messaging on this wasn't clear either no reasons were given specifically other than playstation 3 games are not compatible with playstation 4. the underlying architecture of the playstation 3 would be the major concern it was a massive departure from anything that came before it and indeed anything that would come after coming up with an emulation solution for the playstation 4 with its underpowering jaguar cpu would be an exercise in futility but surely the playstation 5 with its 8 core 16 thread zen 2 architecture fast clock speed and 10 teraflop gpu would make it an ideal candidate for playstation 3 backward compatibility yet sony has not committed to sony playstation 3 in the playstation 5. once again with a blanket response that it's not compatible so why is this the case as well as this we also know that the pc is capable of emulating the playstation 3 with the very impressive rpc s3 emulator that does run at a fairly high level of compatibility and is technically one of the most complex emulators out there the thinking is the playstation 5 hardware should be powerful enough to emulate the sony playstation 3 and if homebrew developers are able to get a high level of compatibility with the playstation 3 via emulation surely sony who owns all the source code should be able to get playstation 3 games running on the ps5 there's definitely some things to consider here so let's start from the beginning the sony playstation 3 is either a marvel in engineering or a horrible mistake depending on who you talk to but for me it's a brilliant piece of engineering the system is packed unique with features and when utilized correctly it was unrivaled the cell processor combined a general purpose power pc core or ppe which featured a 3.2 gigahertz dual core cpu as well as eight additional co-processors known as synergistic processing elements or spes which were also clocked at 3.2 gigahertz taking advantage of these sp es would be complicated even sony's own gaza nordia mauchi of polyphony digital when developing gran turismo 5 would describe developing games on the ps3 as a nightmare the ps3 would also incorporate the rsx or reality synthesizer which was the graphics processing unit developed for the playstation 3. the rsx would be based on the nvidia 7800 gtx and share a lot of similarities with that particular architecture albeit with some modifications in order to get the best performance out of the playstation 3 hardware it was crucial for developers to utilize the spus this would require a significant learning curve and some of the early playstation 3 games would only utilize the ppu and not take advantage of the spus at all one game that comes to mind is ridge racer 7. the main strengths of the spus was to offload mathematical processing to for example things like ai particle engines collisions audio effects rain and many others with all available spus running optimized code it's said that it can still rival modern desktop processing and there's no denying its power but unfortunately this architecture has caused plenty of headaches in the early days many developers struggled to take advantage of the spus because it was extremely complicated to develop for each spu contains a local store of 256k of memory to get data to and from the local store dma or direct memory access is utilized to share data around each unit and a dma transfer can be initiated from the ppu the spus and even the rsx once the data hits the spus the data access is very fast so keeping the spus hydrated with data and running their processors is what you want each spu has 128 registers which are each 128 bits wide or 16 bytes these are suited for fast processing of vector applications if we consider a simple spu program to write a single byte from the spu's local storage to main memory we must first set up a dma transfer begin the transfer wait for the transfer to complete then load 16 bytes or 128 bits from the local memory and if we go the opposite direction in other words writing a byte to main memory it first must be arranged as a 16 byte value and stored in the spu's local memory then a dma transfer must be set up started and cycled until the dma is complete pretty complex stuff for a simple read and write of one byte to and from main memory and if we compound this with the five additional spus plus the ppu which potentially could be running their own processes then the problem becomes much more complex all of a sudden we have to consider things like synchronization memory mapping and communications that require data to be shared across different units emulating the playstation 3 and its spu hardware and the intercommunication between units is a complex problem but the good news is it's already been done rpcs 3 is an open source playstation 3 emulator developed for windows linux and bsd the first public release of this emulator was back in 2012 and its first breakthrough was to run smaller ps3 homebrew this was a good first step because the majority of homebrew would not take advantage of the spus which meant the focus would be on emulating the ppe and rsx to at least get simple homebrew to run flash forward to 2020 an rpc s3 can run many commercial games emulate the ppu rsx and even the spus at a good level of performance and in recent times we've seen some impressive breakthroughs from the rpc s3 team including metal gear solid 4 running at 4k at full frame rate playable all the way through and then demon souls with its 60fps 4k patch as of the making of this episode the compatibility list is almost at 60 of the entire ps3 library as playable with a further 33.5 as getting in game that in itself is pretty impressive stuff but make no mistake this emulator is probably the most complex one ever developed emulating the spus has been a very challenging undertaking i recently reached out to the rpcs3 team for comment about their thoughts that sony would face attempting to emulate the ps3 on the playstation 5. the biggest bottleneck there really is is those spus they really do need some kind of hardware for it to be effective porting rp cs3 can help but without hardware synchronization to emulate the sp atomic memory access it becomes a challenge for performance ideally sony would want to incorporate spu hardware on the motherboard to handle this piece for them mark cerny did mention that the tempest engine has an spu-like cluster for audio processing perhaps sony could leverage this but there's also other issues with regards to the amd architecture on intel processors the x86 extension known as tsx provides a feature set to handle transactional memory rp cs3 makes use of a tsx feature known as rtm or restricted transactional memory it effectively provides exclusive access to a memory block so if another thread attempts to touch the same block of memory the decision process is made by the calling application this tsx extension feature aligns well with the spu's transactional and atomic memory behavior but unfortunately the tsx extensions are exclusive to intel and not available on amd and that includes the zen 2 processor found in the sony playstation 5. and without it a custom software solution must be developed that manages the locking and copying of memory to determine if any memory block was altered this can become quite complex when you're dealing with many spus this means a compromise in performance it is worth mentioning that the rpcs 3 team was able to work around this for ryzen and have come up with a very clever cache line emulation mechanism that emulates the contention problem with minimal locking i also reached out to rob wyatt who worked at insomniac as an engine architecture for the playstation 3. he was a member of the sony ice team and has an excellent understanding of the cell architecture and personally written tens of thousands of lines of spu code emulating the ps3 will be very tricky the most difficult thing of all will be the spus to this day over 15 years later they are still in a class of their own sustained single core performance on an spu is still higher than most anything on the market today writing optimized spu code you are almost writing two programs at once one to manage the data and one to do the math and you'd pair them up so they executed at the same time emulating them would be near impossible on any modern cpu core doing it across multiple cores wouldn't buy you anything rob goes on to say a modern pc runs at a similar clock speed and can do multiply add in a single cycle but it can't sustain it it has to load from memory with cache misses it has to deal with branching it doesn't have enough registers he also confirms that the dma engine was very complex we talked about our simple read write from main memory example earlier and how the dma worked rob confirms that an spu dma can be issued on behalf of another spu because the dma controller itself is memory mapped insomniac developed an spu system for all of its games known as index trim this would provide a 25 graphic boost over the rsx it would utilize any unused spus to pre-cull vertices and off-screen triangles and generate a new indexed list with only visible triangles but as the rsx was processing multiple spus would be modifying the command buffer the rsx had a pre-fetch of 4 kilobytes so if the modification was occurring within 4 kilobytes of the location it was reading from the command buffer wouldn't see it so a semaphore would be utilized so that the rsx would never see any bad data and getting this to work in an emulator rob describes would be a nightmare as this is some very specific hardware features that is on the rsx now consider the tens of thousands of spu programs that can perform very unique tasks and the way that they communicate with the hardware in thousands of different ways our pcs3 does a good job emulating the spus as it stands but it may become very difficult for some use cases for sony to consider playstation 3 emulation it would require some percentage of compatibility which would be perhaps higher than the current 60 of playable rp cs3 games but in conclusion ultimately the challenge cost and time commitment to implement a playstation 3 emulator in the ps5 or indeed any future hardware would be hard to justify the research cost alone would be significant and the budget required for it could not easily be measured given this my personal feeling is that to solve for this sony is just looking to remake as many ps3 exclusives as they can sadly however it may mean that lesser-known games such as puppeteer may be left behind or others that belong to third parties such as metal gear solid 4 by konami may not be interested in a remake and with that i just can't see playstation 3 emulation happening on any sony console its complex architecture is both its biggest triumph and its biggest downfall i wouldn't try anything funny if i were you but it's all not a lost cause i think that playstation 2 and playstation 1 backward compatibility will eventually make its way to the ps5 i would expect some type of announcement with those two systems maybe at some point late next year once the ps5 has established itself and it's basically just off and running with the next generation i do think there is room for ps1 and ps2 to make its way into the playstation 5. but as we've seen unfortunately due to the complexities of the cell architecture and specifically the spus that we went into a lot of detail outlining in this episode it just doesn't seem likely that sony would consider a playstation 3 emulator at this time and i think the only thing that we can really consider going forward is the rc ps3 emulator now before i go i do want to say thank you to kd11 from the rp cs3 team for his very helpful information about emulating the playstation 3 on a pc as well as rob wyatt for reaching out and giving me some really good information as far as the spus go well guys we are going to leave it here for this video thank you so much for watching if you liked it you know what to do leave me a thumbs up and i'll catch you guys in the next video bye for now [Music] [Music] you

Channel: Modern Vintage Gamer

Views: 666,231

Rating: 4.9498577 out of 5

Keywords: playstation 3, sony, ps3, cell, rsx, spu, spes, naughty dog, the last of us, uncharted, mvg, modern vintage gamer, cell be processor, ps3 hard to develop, load hit store, out of order execution, in order execution, last of us, playstation, powerpc, rpcs3, emulation, emulator, intel, playstation 5, ps5, ps3 games

Id: lLebZyha74o

Length: 15min 10sec (910 seconds)

Published: Mon Oct 12 2020

Reddit Comments

[u/DerivIT]

Why do backwards compatibility when they can sell you a digital version, remaster, or remake? /s

[u/-TesseracT-41]

This is, in fact, a new video released today, in case anyone thought differently

[u/lost_james]

M I S T A K E S W E R E M A D E

[u/NoabPK]

Can we just have sonic unleashed on steam so i dont have to play it at -6 fps

[u/danny19901R]

TBH I was playing RPCS3 last night 60fps on ratchet trilogy with minor dips at full 1080p I only have an i7 7700k GTX1060 & 16GB Ram

[u/John_Enigma]

I'm just gonna comment something dumb here: Tmw PS3 has more popularity in been emulated thanks to its years of open-source research and development (and its source of income thanks to Patreon), that the Sega Saturn, which came out in the 90s, still hasn't gotten the same love as Sony's third iteration at all to this day.

Hell, nobody ever had any interest in emulating the OG Xbox until we started seeing progress on both Cxbx-Reloaded and XQEMU.

[u/Fuzzy_Machine_6632]

Lucky you can pick up a PS3 for as low as $15 if you don't still have 1 (here in Japan anyway)

[u/cunningmunki]

Why does the title say Sony PlayStation PlayStation 3?

[u/ihatenamehoggers]

Harder than the original xbox? I think not!