Some interesting Altivec figures

[bloodline]

KennyR wrote:
But anyway, my Pegasos G3/600 can do around 2 million keys per second. My Athlon 1.3GHz PC can do around 4 million. Pentiums are considerably weaker, and maybe more modern Athlons are too.

Well you show me some Athlon64 benchmarks and cheer me up :-D

Anyway, happy new year, and what the hell happened to your boings and Rank?!?! :-o

[bloodline]

Aragorn wrote:
http://n0cgi.distributed.net/speed/
OGR
my AMD Athlon XP Barton 2600+
14,937,961 nodes/sec

PowerPC 744x/745x G4 1000
10,680,517 nodes/sec

That looks about right, and what one would expect if we were to compare Clock Speed of the AthlonXP (rather than AMD PR ratings) and the G4.

That seems to support my argument that clock for clock the modern PPC and Athlons are virtually identical in performance :-)

[bloodline]

Since you know a lot about CPUs, can you answer this - why was an equivalent of Altivec not implemented in x86 cores? Was it a marketing issue (with Altivec speed boost being 'invisible' to consumers, and higher clock speed being very visible)? Was it not possible to implement? Or was it just useless?
 

It is implemented in x86 CPUs, it's called MMX, MMX2, 3DNow!, SSE, and SSE2... :-)

[bloodline]

KennyR wrote:

Bloodline wrote:
It is implemented in x86 CPUs, it's called MMX, MMX2, 3DNow!, SSE, and SSE2...

Boo, they were marketing gimmicks that only slowed the CPU down by adding more instructions to increase the instruction decode time per cycle. Their effect was negligible. Altivec's obviously isn't.

The Altivec is just an FPU that is designed to perform vector math very fast... that is what those "Marketing Gimmicks" are too...

The original Intel version of MMX sucked as it used the x87 registers, but AMD and all later varients of thses units add their own registers.