Re: G4? good? bad?

["Adam Williams" <awilliam@xxxxxxxxxxxxx>]

> so anyhow i'll claim some ignorance and just start this by saying i don't
> really know what a gigaflop is. anyhow i was wondering if there's any
> opinion on Apple's newest chip. I'm sure a few of you hate it. it wouldn't
> sit correctly in the world if the majority of people didn't hate it. but
> they claim it sustains calculations of at least 1 gigaflop and maxes at like
> 4. if this is 100% true and not some weirded out view on the G4 as good ole
> Steve seems to have from time to time, then i wonder if this would be a good
> investment for me to work on buying...


	The G4 (or G3 for that matter) is a PowerPC based machine,  the same
chip used in IBM RS/6000's (and I think the AS/400 now).  The PowerPC chip is a
serious superscalar RISC-ish chip with excellent floating point performance,
and specific circuitry for accelerating common operations used in rendering 3D
(like "MMX" or "3Dwhateverthisweek").  The G3/G4 is a very well designed
machine that reminds one of a real "workstation".  The claims of three times as
fast as a pentium 3 is dubious.  Two diffrent processors cannot be compared by
using the number of operations they perform,  as diffrent processors have
diffrent set of operations.
	Typically a RISC chip needs more operations than a CISC chip (like an
Intel) to do the same amount of work,  but RISC chips often can perform more
operations because they can be made more "superscalar"  (more than one op at a
time via "pipelining") more easily (because every op is simpler than on a CISC
chip),  whether this comes out in the wash as "faster", simply depends.  My
experience on PowerPC boxes (RS/6000s in my case) is that they perform the same
as an Intel chip on most apps,  but kick Intel's teeth in on number crunching
(no suprise),  it depends on what you do.  And for graphics is depends on
whether your application and/or OS supports the MMX-ish extension of the week
whether those really help you,  most of the time applications don't support
that stuff as it often requires inline assembler and ruins a programs
portability,   games are where those "multimedia extensions" really buy you
performance as game programers are more likely to use them.
	But a CPU is not a machine,  you still need I/O, memory, and buss
performance to really get the money out of one of these things, and in that
regard the use of ATA is a suprising step back for Apple,  but they probably
know that consumers CPU shop, so they can get away with it.