Re: Choppy MP3 and DVD playbacks

[David Mosberger <davidm@napali.hpl.hp.com>]

>>>>> On 16 Nov 2004 19:09:24 +0100, Emeric Maschino <emeric.maschino@jouy.inra.fr> said:

  Emeric> I didn't notice such faults. Just to understand. I thought
  Emeric> that floating-point software-assist and unaligned access
  Emeric> faults were specific to a given arch (IA-64 in this case). I
  Emeric> mean, if there is no such error on an Itanium-2 system,
  Emeric> there will be no error on an Itanium (first generation)
  Emeric> system, and vice versa. Is this correct or am I wrong?

The architecture _allows_ for these faults, but does not require any
particular CPU to use them.  For the most part, Merced- and
McKinley-based CPUs will fault for the same reasons, but the details
can definitely vary.  For example, on Merced if PSR.AC is off, you'll
get an unaligned fault only when crossing an L1-cache-line boundary
whereas on McKinley you'll get a fault when crossing an 8-byte world
boundary.

  Emeric> do you notice such faults when listening to MP3 tracks on
  Emeric> your Itanium-2 system?

That may of course depend on the player, but I don't see any faults
with xmms or xine.  That's all I tried.

	--david