Re: Plan 9 grids with AMD64 CPUs

On Sat, 29 Nov 2003, Charles Forsyth wrote:

> i'm curious about this: apart from the hype and artificial benchmarks,
> for an arbitrarily chosen real computational program, how much faster is
> it?

depends. if your code needs > 4 GB memory, it's a bit faster. 

recall that the 8086 was at first no faster than a z80, and vax no faster 
than pdp-11. cutover takes time.

K8 is a really nice arch in 64-bit mode

> another justification i've seen that does make sense is to use 64-bit
> addressing for applications that need a huge directly-addressible memory
> (not that there are too many of those applications, or that they
> couldn't be a bit cleverer).

well, no, sometimes they can't be more clever. when you divide, e.g., the 
earth into a certain number of chunks of certain size, you end up needing 
lotsa memory.

ron