[ydl-gen] Looking for advice.

[Stephen Harker]

Hi,

I have a somewhat different perspective from Warren, though I agree
with some of his comments.  

> 3. Again, YDL runs just about anything that all other linuxes run. An  
> annoying exception is Flash, which doesn't run on the ppc  
> architecture. There is a 3rd party replacement (whose performance  is,  
> in my opinion, unacceptable). 

Personally I find flash to be of no interest.  But this is very much a
minority viewpoint these days.

> There are lots of apps in every category  
> which run fine in YDL, though whether they are better or worse than  
> commercial apps in OS X is something you need to decide. I tend to  
> prefer the commercial apps, though a lot of effort has gone into  
> making Open Office a decent clone (I actually run none of the office  
> apps, commercial or not).

I have had little use for most commercial applications.  I mainly use
TeX (I prefer to use the TeXLive distribution and install that
myself).  For creating graphics, plots and such I have mostly used
gnuplot (4.2.3 as of the moment), R and xfig.  I have made limited use
of ImageMagick and gimp for photo type graphics.  For most other needs
I largely am using self-compiled, often self-written, data analysis
programs.  For this the supplied compilers are adequate.  I would like
a later gfortran (and gcc generally) than the supplied 4.1.2.  I
notice there are packages such as: spu-gcc43-4.3.2-2.ppc.rpm supplied,
but have not investigated them further.

> 4. The installation documentation is excellent and should make it easy  
> to install on your iBook.
> 
> One caveat: The graphics in PPC linux (any distro) leaves a lot to be  
> desired.  The video processors are very badly supported in PPC linux -  
> the GPU companies provide no drivers for ppc and the 3rd party ones  
> (reverse engineered) range from very bad to barely acceptable. The  
> graphics in linux doesn't compare to that in OS X. This was what  
> eventually drove me to give up on linux - good video is very important  
> to me, but other people might not feel that way and might find linux  
> ppc graphics perfectly acceptable.

In general accelerated X11 should be available, but there seems to be
a problem with the supplied kernel.  From memory some form of
accelerated X11 has been available since around 2002 for r128, for the
later radeon the availability has varied, but all bar the latest
iBooks (late 2005 with ATI Technologies Inc M11 NV [FireGL Mobility
T2e] (rev 80)) have been well supported since 2005!  This accelerated
X11 support may not be up to Apple's Quartz, but was quite
reasonable.  People with 2004 iBooks had accelerated X11 since YDL4.0,
I remember a colleague with a 2004 iBook who was really pleased when
4.0 came out as it enabled a big improvement in graphics performance.
However, he had problems with YDL6.1 graphics performance until he
compiled his own kernel (linux-2.6.27.8 worked for him as it had for
me). 

With my late 2005 iBook it has not been since much later
kernels and Xorg releases that accelerated X11 has been available.  In
terms of YDL, the 6.0 release had a limited accelerated X11, but the
big improvement came with YDL6.1 with a self-compiled kernel
(linux-2.6.27.8 again).  With my current kernel and a standard window
for glxgears I get:

glxgears 
5127 frames in 5.0 seconds = 1025.024 FPS
5325 frames in 5.0 seconds = 1064.919 FPS
4699 frames in 5.0 seconds = 939.784 FPS
5687 frames in 5.0 seconds = 1137.294 FPS
5076 frames in 5.0 seconds = 1014.211 FPS
5157 frames in 5.0 seconds = 1031.296 FPS

-- 
Stephen Harker                           s.harker at adfa.edu.au
PEMS
UNSW at ADFA