PS3 Cell, RSX, SDK, OS, Linux INFO

[DieH@rd]

Coppied from neogaf thread

original japanese articles:
http://pc.watch.impress.co.jp/docs/2006/0922/kaigai302.htm
http://pc.watch.impress.co.jp/docs/2006/0926/kaigai303.htm
http://pc.watch.impress.co.jp/docs/2006/0926/kaigai304.htm
http://pc.watch.impress.co.jp/docs/2006/0926/kaigai305.htm

And a traslation by Doctor_No

Here's a more complete translation:

I'll combine the two articles since some of it is redundant

NOT COMPLETE, WILL BE UPDATED. . .
Edit: half the Linux section added. . .
working on the rest of the Linux article

Slow updates on the PS3 SDK

The article goes into some hurdles PS3 developers had to go through. SDK 1.00 was supposed to be released by TGS, but the latest release before TGS is 0.93. What is shown at TGS is still developed with SDKs that are not final.

This situation is similar to Sony’s PSP launch with slow SDK updates, however the situation may be worse. According to Sony’s Spring schedule SDK 1.0 was planned on being released in June.

The SDK version number is relative to hardware maturity and 1.0 release may take awhile. The developers will have to debug using non-final SDK. This may indicate that SCE software development has not caught up to schedule in regard and previously may have been over optimistic. Several PS3 “DebugStations” are finally starting to reach the hands of developers, with about 2-months till launch were concerns on schedule before TGS.

Hurdles involving the Performance of the Cell:

There are some challenges involving the architecture of the Cell, the cell consists of PPE and SPE cores. A developer states, "It is impossible to extract the full performance of the Cell on launch titles, it will take time get familiar with it". Another developer states that they are having difficulties with the 256KB memory of each SPE core. The actual useable area of the 256KB is closer to 128KB when buffering is considered with accessing external DRAM. "It would have been much different situation if there was 1MB of local memory”. There is however a benefit for these restrictions on local memory, since latency can be reduced, and latency cycles are more easily read. This is an advantage for real-time gaming applications.

Till now, developers were stingy with programming and memory usage, and this will not change with the PS3, in fact, the Cell will reward developers that put more effort into programming. While that may not be a negative, it is a hurdle that will take larger developer resources and time. For the Cell it has changed from extracting performance from the hardware, but more towards multi-threaded performance and takes a different skill set then the previously.

RSX Memory Bottleneck

Developers were using 7800GTX for development, The RSX uses Nvidia’s G70 and performance programmable shader performance is very high. But the memory interface is 128-bit, in addition 8 ROP (Rasterizing Operation). It can be said that the RSX has a shader equivalent of a high-end PC with mid-range memory bandwidth. For that reason, due to the GPU high shader performance there is a bottleneck to the ROP memory and is causing a bottleneck. “For lower resolutions it is a fantastic GPU, but it gets difficult for high end HDTV resolutions”, says a developer.

The biggest impact is the HDR and FSAA, the memory bottleneck becomes hard for PC levels of HDR and FSAA, to overcome this hurdle developers are using memory from the Cell for textures, and using FlexIO as a texture lead to reduce GPU bandwidth issues.

Developers are having exactly opposite problems then that of the PS3 and 360 as far as GPU performance is concerned. While there memory bandwidth issues with the PS3, they have great shader performance. For the 360, they have little memory bandwidth issues with the 10MB eDRAM, and less FSAA issues. But some developers are having issues with a lack of shader ALU performance and threading resources, however performance will increase as developers get more familiar with unified shader architecture.

However, all hardware has its limitations, and the real difference should be felt as the two systems get mature. For the PS3, developers are having concern if they can truly exhibit the difference in power between the PS3 & Xbox 360 due to technical hurdles.

TGS: Progress in game development

Many of the concerns and criticisms for the PS3 including price, technical difficulties are similar to the PS2 when it was first released. Many in the industry had expected the PS2 to fail before its release, but the contrary became true. A lot of the concerns have been reduced due to the change in spec and reduction in price of the PS3. It is unclear if price reduction and its impact on long term success.

After PS3, developers are more aware how other PS3 games are shaping up. Before TGS developers were largely unaware of how other PS3 software was in terms of development and quality. One developers says “we were surprised that the hurdles we had in development were also overcome by other developers”, others had praises and complaints on where their rivals were along on PS3 titles. At this pre-launch stage there were high and low points especially with the new hardware.

The PS3 technical issues are growing pains that all hardware goes through. The complexity of next-gen hardware means that time for developers to get used to the hardware would be much longer then previous generation. Even looking at the Xbox 360, one is able to see improvements in development in first-gen and upcoming second-gen games after a year since its release. In other words, for this generation, it will be more evident the difference in games with more work put into them due to the complexity of the architecture. It has become harder to judge a system by its launch titles.

SCE: goal of creating an entertainment computing platform

SCE is planning on making the PS3 into a wide ranged entertainment computing platform. SCE wants the PS3 to not only do games but also host a wide range of entertainment applications. For that reason, the HDD will be standard on the PS3 and will adopt and open programming environment. The Cell OS, which runs games will be security locked, but for other applications the Linux OS will be free to turn any application. Unlike the situation with the PSP, Sony’s attitude will be creating an environment for applications to be developed for the PS3.

However, this new SCE tactic will mean that the business structure will need to change dramatically. The reason is to develop a platform there needs to be proper funding by licensing fees to make it viable. What SCE is aiming for is a computing platform, akin to Intel/Microsoft or Intel/Apple. Sony is aiming for entertainment applications for the living room.

Kutaragi has previously stated that they will not take an OEM approach to this business and do not plan on charging for the OS such as Windows. It is in his belief that the OS should not be charged separately. However, financially, Sony will need to succeed on the PS3 sales and profitability to make this open platform financially feasible.

Comments?

 

[babcat]

The important thing to discover is you can run any application on the Linux OS. For example, could I go out and purchase a Linux based OS with a full graphical user interface and run it on my PS3? And if so, would it utilize the power of SPEs and not simply the PPE which is relatively weak compared to the SPEs? That is the important issue.

 

[pcostabel]

The Linux stuff will work exactly as with the PS2: a special PS3 distribution with no BD access. You will be able to recompile any apps that are open source. Of course no other distribution will work if is not ported specifically to PS3.

 

[patsu]

The Linux stuff will work exactly as with the PS2

I hope for tighter integration between XMB and Linux.

I'm also interested to find out how Cure@Home works. Apparently, it can run while PS3 is idle. So there should be some sort of OS mechanism to schedule idle tasks too.

Thanks to DieH@rd for the OP.

 

[SPM]

The Linux stuff will work exactly as with the PS2: a special PS3 distribution with no BD access. You will be able to recompile any apps that are open source. Of course no other distribution will work if is not ported specifically to PS3.

It will be different from PS2 because of the SPE reserved for DRM. Sony can allow Linux access to the BD drive without blowing the box open if they want. They may restrict the number of SPEs or reduce graphics rendering speed or something like that to discourage development of high end games running on Linux, although the fact that Linux will take up a lot of the available RAM will discourage this anyway.

 

[PSman]

Very interesting, especially on the RSX and Xenos part.

I think it is safe to say that RSX=Xenos, both GPU have their own advantage and disadvantage:smile:

 

[joebloggs]

Very interesting, especially on the RSX and Xenos part.

I think it is safe to say that RSX=Xenos, both GPU have their own advantage and disadvantage:smile:

Yeh they both have their advantages.

RSX has more shader power.
Xenos has the EDRAM for bandwidth.

 

[SPM]

Yeh they both have their advantages.

RSX has more shader power.
Xenos has the EDRAM for bandwidth.

Xenon/Xenos also has memory bandwidth issues.

Cell and RSX have separate 128 bit busses to XDR system RAM and GDR, hence not contention between RSX accessing GDR and Cell accessing XDR, and a little more than double the total bandwidth.

However Xbos360 has a 128 bit bus to the unified 512MB system RAM and both Xenon and Xenos have to contend access it.

How much of a bandwidth is this for both Xenon and Xenos?

 

[DieH@rd]

and here is final part of translation:

Evolving PS3 platform

Hitherto, game systems have made a profit based on royalties from game sales and were based on a license model. However, in a PC-style business model, Microsoft does not profit from license model with their Windows platform. Application development is free and open as a platform. For this reason, Sony cannot charge licensing fees outside of gaming. The current business model does not fit this new evolving platform.

For the PS3 to succeed as a computing platform, Sony will need to succeed as a gaming platform first. The PS3 platform is a much larger undertaking for Sony then before, Sony will need to develop and support middleware and tools for the PS3 Linux. Sony themselves will also need to develop attractive applications and services for the platform as well. Part of the PS3 high retail value can be attributed to this factor as well.

and:

As the image shows, the OS will be run off the flash memory that is on the PS3 instead off the optical media like the PS2. There is also another seperate install of OS on the HDD (Linux), the Cell OS will be locked from the Linux OS to prevent piracy. But Sony is promoting homebrew on the PS3 (unlike the PSP), the article states that they want the PS3 to be a computing platform like Windows/Mac and Linux. Also confirmed that cell Hypervisor will be included on the flash memory of the PS3, which I guess is kinda like Microsoft's Virtual Server and EMC's VMware.

http://www.research.ibm.com/hypervisor/

So, ps3 OS will be stored to flash memory... I wonder how big it is?

 

[SPM]

and here is final part of translation:
So, ps3 OS will be stored to flash memory... I wonder how big it is?

The image actually shows Linux on the HDD http://pc.watch.impress.co.jp/docs/2006/0926/kaigai303.htm
- and a good thing too since flash memory is very slow compared to HDD for reads (and even slower for writes).


The PS3 OS they are talking about is the PS3 hypervisor, DRM and menuing system.

 

[Angelcurio]

So, the OS wont be using part of the main ram anymore?

 

[StefanS]

So, the OS wont be using part of the main ram anymore?

You're confusing something...

physical storage != RAM use

 

[KOA]

Yeh they both have their advantages.

RSX has more shader power.
Xenos has the EDRAM for bandwidth.

Where does it say RSX has more shader power??? It does say that X360 devs are having a hard time getting shader performance currently, but that it will change once they get more familiar with USA.

 

[Arwin]

Where does it say RSX has more shader power??? It does say that X360 devs are having a hard time getting shader performance currently, but that it will change once they get more familiar with USA.

And I reckon the same goes for the bandwidth - except that 360 developers seem to have as much trouble getting much out of the EDRAM as the PS3 coders have getting used to making good use of the XDR/Cell bandwidth. Maybe more, we'll see today!

 

[KOA]

Both consoles seem to be on an equal footing on paper. It's too close to call at this point. At this point, specs sheets are useless. We have to look at the games. After TGS it's Sony 1 Microsoft 0 (although Blue Dragon and Lost Odessey look better than some PS3 games at the show), but PS3 games have that "LOOK" that has less to do with technical stuff and more to do with the developers. PS3 developers know how to add that "next gen filter" while X360 devs outside of Capcom and Epic just add more polygons and textures and have that plastic look.

But, I don't want to make a fool out of myself before X06, so I'll just shut up about how "bad" X360 games look in comparison to polished PS3 stuff.

 

[Bobbler]

Where does it say RSX has more shader power??? It does say that X360 devs are having a hard time getting shader performance currently, but that it will change once they get more familiar with USA.

I'm not quite sure I really understand that argument... isn't the whole point of unified shading to alleviate any issues with having to match a specified ratio of VS/PS? There shouldn't be any inherent issues with trying to max out a unified architecture, it does that itself -- that's the whole point of it, it has an inherent flexibility so developers could throw whatever they wanted at it within a certain max amount of ALU performance (between VS and PS). If they are having ALU performance issues, that isn't likely to be the kind of thing that will drastically change (beyond the average change in programming competence that comes over the lifetime of a platform -- which is seemingly quite a bit). If they are having issues with USA, then they'd have equal or possibly more issues with a non-unified architecture; the same improvements would apply to both.

I'm not trying to say RSX is more powerful than Xenos or anything, I just don't buy the "leaning the USA" as any sort of special case that only applies to Xenos. I think both GPUs are pretty close to each other (different bottlenecks at any given point, but definitely same year parts).

 

[SPM]

Both consoles seem to be on an equal footing on paper. It's too close to call at this point. At this point, specs sheets are useless. We have to look at the games. After TGS it's Sony 1 Microsoft 0 (although Blue Dragon and Lost Odessey look better than some PS3 games at the show), but PS3 games have that "LOOK" that has less to do with technical stuff and more to do with the developers. PS3 developers know how to add that "next gen filter" while X360 devs outside of Capcom and Epic just add more polygons and textures and have that plastic look.

But, I don't want to make a fool out of myself before X06, so I'll just shut up about how "bad" X360 games look in comparison to polished PS3 stuff.

I always considered the "plastic" look of Xbox1 games compared to the PS2 was down to th fact that PS2 was good at particle effects, while Xbox1 wasn't. So PS2 developers used in particle effects a lot and Xbox1 developers didn't. It may be the same with PS3 vs XBox360. The SPEs should be good at particle effects while Xenon is less good, although it might also be handled by the GPUs in this gen.

 

[Angelcurio]

You're confusing something...

physical storage != RAM use

Sorry, i confused eveything when i read it this morning.

*notes that wont post anymore before drinking my coffee on the job*

Now, in a real note. I always thought that the OS was going to be located on a reserved space of the HDD. That was prior the sony announcement of the users being able to swap the default HDD for any SATA drive.

 

[Dr. Nick]

I wonder how many devs still use the Xenos in a non unified way. I remember it being implied that a dev could still use it in a non unified way.

 

[Shifty Geezer]

There's a difference between system OS and the user operating system. It's like Amiga's OS was on it's kickstart ROMs, but the OS people used, AmigaDOS and Workbench, was loaded from disc. PS3OS system OS is in Flash, Linux or other user OS's is on HDD, and Linux (supposedly, still not confirmed!) comes preinstalled on the HDD.