the right distro for the PS3

[trj021782]

I am currently using Ubuntu on my PS3 because I have had experience with Ubuntu in the past, however that was all x86 architecture and I have since come to find out that Yellow Dog is all about the PPC/Cell architecture. I have noticed some performance issues out of my copy of Ubuntu so I have been putting serious thought into going Yellow. So here is my question, Is Yellow Dog optimized to deal with the criminally low amount of RAM available on the PS3?

P.S. just in case anyone out there was going to mention it I have already mounted the VRAM as swap so I *kinda* have 512 but that is still a ridiculously low amount

[billb]

I can't provide any memory use comparison for YDL vs Ubuntu, but I don't normally run into memory problems unless I'm compiling certain applications. I recently started using XFCE4 instead of Gnome and it seems a little "snappier" on that, too. I don't care so much for E17/Enlightenment which is the default environment for YDL (easily changed at the login screen).

Depending on what resolution you're running, you can also reduce the memory dedicated to the frame buffer -- you can gain anywhere from 0 - 10 MB system RAM this way. You can gain even more if you never use any applications that use double-buffering (like scaler, fscaler, or that IBM ray tracing demo).

At 720p you can safely reduce the memory provided to the frame buffer from 18MB down to 8MB. On YDL this is done in /etc/yaboot.conf by adding ps3fb=8M to the kernel boot options. Not sure how it's done on Ubuntu. You just have to make sure you don't reduce it too much for the video mode you're running. 1080p needs 16MB, and 1920x1200 needs the full 18MB.

[ppietro]

I am currently using Ubuntu on my PS3 because I have had experience with Ubuntu in the past, however that was all x86 architecture and I have since come to find out that Yellow Dog is all about the PPC/Cell architecture. I have noticed some performance issues out of my copy of Ubuntu so I have been putting serious thought into going Yellow. So here is my question, Is Yellow Dog optimized to deal with the criminally low amount of RAM available on the PS3?

P.S. just in case anyone out there was going to mention it I have already mounted the VRAM as swap so I *kinda* have 512 but that is still a ridiculously low amount

Personal opinions to follow:

To be honest, unless you're comfortable with switching from Debian based Linuxes (like Ubuntu) to Red Hat based Linuxes (like YDL), you're better off staying with Ubuntu.

In addition, YDL is not based on Fedora, but the more conservative Red Hat Enterprise Linux. This means that the libraries are about 3 years older than current Fedora builds.

More about this here:
http://en.wikipedia.org/wiki/Red_hat_en ... tributions

That doesn't mean you can't do cool stuff with YDL - it's just something to bear in mind.

As far as memory usage, I think ps3ubuntu and ydl memory usage is about the same. We use the same 256 Meg RAM + 256 Meg VRAM swap that you have now. YDL 6.2 does allow a PowerPC/Altivec replacement of glibc with libfreevec.

If you're having memory issues, you might try changing your Window Manager from Gnome to something lighter like Fluxbox or XFCE. That helps on the PS3.

Cheers,
Paul

[trj021782]

So the resounding theme here is that YDL is not more optimized for the PS3's CELL architecture than Ubuntu, I ask because I know that I will never get screaming performance out of any modern OS running on such an incapable system (incapable due in some part to the hypervisor) but I would like it to be less crappy. I suppose I will mess around with Ubuntu a little more but if things do not improve this OS will force my hand.

Also I am not afraid to switch away from a Debian base. I am still new enough to linux that I will be in the market to learn no matter what, I mean it isn't like going from 20 odd years of DOS/windows use to trying to figure out Unix/Linux - it is really just a different shade of grey at this point.

***EDIT***

P.S. aww man, I don't wanna switch away from 1920x1080 . . . . . . it feels like such a waste on this great tv

[ppietro]

So the resounding theme here is that YDL is not more optimized for the PS3's CELL architecture than Ubuntu

More of my thinking out loud:

The way I understand it, that's an issue with the monolithic kernel structure of Linux, not Ubuntu, YDL or even the PS3 at all.

The main issue is that the Linux kernel doesn't understand a processor that doesn't have symmetrical processing cores. By this, I mean cores that execute the same OP codes - base assembly language.

It's my understanding that Linux kernels can't really take advantage of the PPE/SPE mix of the Cell, since they have different processor instructions. They would only be able to use the PPE or the SPE - but not both. Since the SPEs aren't completely Turing compliant - they don't really execute programs as much as act on data - Linux can only use the PPE. Unfortunately, the PPE is pretty much weak sauce, since, for the most part, it's designed to set up the SPEs. (PPE = moderately fast, single core, twin thread, in-order PowerPC processor.)

To really use the Cell efficiently, you'd have to use a kernel capable of parsing out instructions to other nodes, with mixed architectures. In my mind, this would be something like the Mach kernel that Mac OS X is based on - or even GNU/Hurd. (I would have no idea where to start with this, though. )

As far as the hypervisor goes, the main issue we've found is the inability to access the nVidia RSX directly. The framebuffer display - although fast - is completely CPU driven. That's an issue since, with Linux, that means the PPE has to drive it, splitting frame tasks with all the other processing it's doing.

In some ways, the hypervisor is a good thing. It helps abstract the custom PS3 hardware to look more like a PC - this lets fairly standard distributions of Linux run on it. Otherwise, there'd have to be a lot more custom drivers - for disc access or memory control, for example.

As far as Cell-specific tweaks, YDL is pretty good. It supports the using the VRAM as a swap drive out of the box. It also supports libfreevec, which accelerates glibc with the AltiVec core on the PPE.

It also supports running true Cell programs without system modification - the necessary SPE libraries are included. You can download Cell demos directly from IBM, for example, and they'll run without adding additional libraries. An example is here:
http://www.alphaworks.ibm.com/tech/irt/download

You can also compile PPE optimized and true SPE code with the default software development installation. So - it's mainly for that reason that YDL says it's optimized for Cell architecture. But - that's mostly software development only. It isn't going to help with day-to-day tasks like running Firefox, or OpenOffice, etc.

And - with very, very few exceptions - there haven't been enough PS3 Linux users to develop SPE accelerated drivers. A perfect application of this would be a replacement of the default X11 video driver with an SPE accelerated driver, offloading the drawing code from the PPE.

The only developments in this area have been a partial SPE accelerated mplayer driver, a partially completed SPE based OpenGL driver, and an SPE scaler to allow you to scale up 8 bit emulators so the PPE doesn't have to handle the 1920x1080 pixels.

True Cell-optimized Linux would take a re-think of the base principles of Linux in general, based on the way I understand it.

That - or we need a 2nd generation Cell processor with an actual G5 in it, instead of the PPE.

Cheers,
Paul

[trj021782]

Don't hold your breath waiting for that second gen Cell, IBM recently announced that they are giving up the Cell architecture because of low market response.

I would have linked you to an article if this PS3 browser weren't a total s#!t box

[billb]

Don't hold your breath waiting for that second gen Cell, IBM recently announced that they are giving up the Cell architecture because of low market response.

Is this anything different from the announcement made back in Nov. 2009?

[trj021782]

I am not certain when the statement was released, I just know it was recent. However your comment sounds like a foolish question, How many different times has IBM said they will no longer make the CELL processor?

***EDIT***

Also this entire thread has very nearly become a load of horse s#!t. I came here for practical advice on how to improve the performance my PS3 while using Linux, assuming that perhaps I had done some thing foolish that new people do all the time resulting in this OS running crappy and instead I am told for hundred-millionth time that the PS3 has "AMAZING POWER!!!!" that no one can utilize. All of this culminating in an end user experience that I could have easily exceeded with K6-2 from pre-2000. So now, I stand before you, as a Christian, being asked to believe in a power that no one can prove yet, unlike Christianity, continues to be a pain in my a$$ and a source of constant sorrow. So I say once more, Is this system capable of doing even the most simple of multi-tasking requests or must I always decide between listening to music or surfing the Internet?

P.S. - Before any of you who may fancy yourselves as smart a$$es come back here and post about appropriate effort being put into utilizing this OS, know this - I am made of nothing but effort however effort without gratification will eventually run out.

[billb]

Well it was really the "as a Christian" part that did it for me. Take a break for a week, or longer if you please.