anon (anon@anon.com) on 11/17/10 wrote:
---------------------------
>someone (someone@somewhere.com) on 11/17/10 wrote:
>---------------------------
>>Richard Cownie (tich@pobox.com) on 11/17/10 wrote:
>>---------------------------
>
>>>But for sure, if Intel are really going to keep on building
>>>new IA64 cpu's, they should make them as good as they can,
>>>whether OoO or not. I just don't see any reason to think
>>>that an ISA contorted to avoid the need for OoO and
>>>register renaming is magically going to provide benefits
>>>for an OoO implementation. That would be very weird.
>>>
>>
>>It burns a lot of power using hundreds of thousands of
>>logic transistors re-discovering something about a scrap
>>of code every single loop iteration or subroutine call for
>>every execution of all copies of program that one compiler
>>need only to discern once. Everything can't be discovered
>>at compile time but it is stupid to ignore that which can
>>be and then passed on using a suitable equipped ISA.
>
>I don't think you can really call a sane OoOE implementation "heroic" and "burning
>lots of power" any more.

The OOOE logic in the Pentium M consumes about 26%
of device power and twice as much power it uses actually
doing computation (i.e. integer and FP data paths). Going
wider issue and/or larger window burns disproportionally
more of the power budget.