Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Multiple processors on one chip...

Author: Jeremiah Penery

Date: 19:19:51 03/03/00

Go up one level in this thread


On March 03, 2000 at 20:05:57, Tom Kerrigan wrote:

>On March 03, 2000 at 17:08:58, Robert Hyatt wrote:
>
>>Problem is the compilers don't know what is going on.  IE how many "hidden"
>>registers does the architecture have for renaming?  Intel (nor anyone else)
>>will make this a 'constant'.
>
>But my point is, why have register renaming at all. I can list a dozen good
>processors that don't do it. I would like to know the exact percentage speedup
>it gives you.
>
>>And how does the P5 do more per cycle than a P6 when the p6 can do three
>>ops/cycle, while the P5 drags along at a max of 2, and it requires a very
>>good compiler to do two at a time???
>
>TSCP (1.42) on an original Pentium/200 searches 136 NPS/MHz.
>
>On a Pentium II/300, it searches 119 NPS/MHz.
>
>So the Pentium appears to be 15% faster, despite its lack of out-of-order
>execution, branch predition, speculative execution, register renaming,
>reservation stations, blah blah blah.
>
>I assume this is because the P5 has shorter pipes and doesn't have to flush them
>all the time due to speculative execution gone wrong.
>
>(BTW, the K5 has almost everything beat. It searches 173 NPS/MHz, and it doesn't
>do anything particularly fancy either.)

Maybe your original statement should have been more like: "_For TSCP_, the
original Pentium does more work per clock-cycle than the PII."  Because this
will likely not be the case for other programs.  I know a lot of programs favor
the AMD chips over the Intel ones.  There are other programs that highly favor
the Intel chips.  Crafty, for instance, does a bunch more work/cycle on the
Intel P6 chips than it does on any other chips (not including Alpha and such).



This page took 0.02 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.