#1547 HIGH Trial-2: Decide frame buffer depth - 565 vs ARGB 8888

[Zarro Boogs per Child]

#1547: Decide frame buffer depth - 565 vs ARGB 8888
-----------------------------+----------------------------------------------
 Reporter:  jg               |       Owner:  cjb    
     Type:  task             |      Status:  new    
 Priority:  high             |   Milestone:  Trial-2
Component:  x window system  |     Version:         
 Keywords:                   |    Verified:  0      
-----------------------------+----------------------------------------------
 This one isn't obvious.  Going to 24 bit frame buffers uses more memory;
 but how much?

 Having true alpha in the frame buffer/window system is useful for UI.

 GX's can't alpha blend between different depths: unless Cairo, upstream,
 decides to reinstate 565 as a full fledged citizen, we are stuck with
 software conversions all the time.

 Touching twice as much memory also has performance consequences.  But
 power consumption may be much improved on GX (not that we care long term,
 but we do care that the trials work well until we're in production and
 machines with 128 meg of RAM are retired from children's hands).

 First thing to do is get some data....  Making this decision is non-
 obvious and non-trivial.

-- 
Ticket URL: <http://dev.laptop.org/ticket/1547>
One Laptop Per Child <http://laptop.org/>