Graphics Performance

[Carsten Haitzler (The Rasterman)]

On Thu, 02 Apr 2009 21:19:45 -0400 "Iain B. FIndleton"
<ifindleton at videotron.ca> said:

> Well, that clears things up a bit. So, there is no way to get rid of the 
> draping one sees when the display is refreshed? My stuff uses double 
> buffering, but your comments appear to indicate that that is a waste of  
> time.

draping?

> Carsten Haitzler (The Rasterman) wrote:
> > On Thu, 2 Apr 2009 18:23:38 +0200 Tobias Diedrich <ranma
> > +openmoko at tdiedrich.de> said:
> >
> >   
> >> Iain B. FIndleton wrote:
> >>     
> >>> A significant issue for me is the performance of the graphics display on 
> >>> the FR. I recall some discussions a while back about making use of the 
> >>> XGlamo acceleration features. Has any progress been made here? It 
> >>> appears to me that the graphics performance on the FR is poor compared 
> >>> to, for instance, the iPhone or iTouch, both of which have slower CPUs. 
> >>> When applications running on the FR have their X output routed to a 
> >>> machine with accelerated graphics, it is apparent that the FR processor 
> >>> can deliver the X events fast enough, but the FR graphics chip interface 
> >>> can't keep up.
> >>>       
> >> Isn't the glamo supposed to have one (or more?) OpenRISC cores?
> >> It would be nice to have a documented way to upload code to the
> >> core, that way it might be possible to implement the Bling on the
> >> graphics chip directly...
> >> I mean, since OpenRISC has a documented instruction set (unless
> >> they've augmented it) set I'd figure the only thing missing would
> >>  be where to put the code and how to start it...
> >>     
> >
> > this information is not even in the docs openmoko had on the glamo. there
> > is no known way to play with this core. my understanding is that it is
> > actually a relatively slow core (50mhz) and is only really for higher level
> > management of sub-systems on the glamo.
> >
> > of course here is your big problem.. you can do all this for the glamo and
> > it will never work anywhere else. it is a 1 off for 1 chip that will never
> > see the light of day in another product.
> >
> >   
> >> So, just like with the mpeg4 decoding unit, wouldn't it be
> >> possible for someone with access to the NDA documentation to write
> >> an example program that just shows how to run a simple program (e.g.
> >> bitblt) on the OpenRISC processor?
> >>     
> >
> > no. as those docs are not even in the nda docs. other than that.. bitblit is
> > documented and not related to the risc core. there is a blitter there.
> > xglamo uses even. xglamo *IS ACCELERATED* it's about as accelerated as most
> > x drivers (fills, blits). it has no accel for xrender (xglamo doesnt
> > implement enough of xrender's operations to make it worth it - again see my
> > previous mail. you'll be writing fallback software code and end up no
> > faster than where you started).
> >
> > if you want decent speed - drop to qvga. thats what glamo was really
> > designed to handle. even the 2442 (cpu) is pushing it to deal with vga
> > nicely. it can. but that generation of cpu is more geared to qvga
> > resolutions.
> >
> > the gta02 is a ferrari body (vga screen) with a lawnmower engine under it
> > (2442 +glamo). you need to drive it like a lawnmower - and then only expect
> > it to be as good as a lownmower. it looks nice parked on the street (still
> > photos) but if it moves... it will show its true nature. remove the heavy
> > ferrari body and drive it like a go-kart and you'll have more fun.
> >
> >   
> >> -- 
> >> Tobias						PGP:
> >> http://9ac7e0bc.uguu.de
> >>
> >> _______________________________________________
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> >> community at lists.openmoko.org
> >> http://lists.openmoko.org/mailman/listinfo/community
> >>
> >>     
> >
> >
> >   
> 
> 
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-- 
------------- Codito, ergo sum - "I code, therefore I am" --------------
The Rasterman (Carsten Haitzler)    raster at rasterman.com