[OT] End-user uses for x86-64 (was: Why are still not at 64 bits)

[Jim Kuzdrall]

On Friday 16 February 2007 14:27, Michael ODonnell wrote:
> >> End users of portable processing may benefit from clock rate
> >> reduction.  The 64-bit internal and main memory paths double the
> >> processor's instruction throughput.
>
> If all data paths doubled in width you'd certainly see increased
> througput/efficiency.  But many internal data paths in current
> designs are already wider than 32bits, and cache line sizes (which
> dominate the nature of exchanges w/main memory, and which are
> also already quite large) wouldn't necessarily double just because
> your programming model now allows you to utter 64bit addresses.

    I did say "Almost".  Certainly, all of the FPU data lines are 64-bit 
- they even were in the 486, weren't they?

    What most users will observe as higher performance won't come from 
the CPU.  The CPU already spends an awful lot of idle cycles waiting 
for I/O.

    Faster mass memory (a replacement for mechanical disks) and faster 
Internet transfers will sell a lot more computers than doubling 
processing speed.

    If the economies of fabrication make a 64-bit designs as cheap as 
32-bit designs, then the lower power might give a minor advantage.

    Actually, what will happen is quite simple.  Microsoft buys large 
stake in Intel.  Vista-2010 will only run on 64-bit processors.  Quick.  
Buy Intel stock.

Jim Kuzdrall