Author: Matt Taylor
Date: 22:56:11 02/12/03
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On February 12, 2003 at 21:07:57, Robert Hyatt wrote: >On February 12, 2003 at 16:13:29, Tom Kerrigan wrote: > >>On February 12, 2003 at 11:47:21, Robert Hyatt wrote: >> >>>But I don't >>>think OOOE is _nearly_ as important for decent architectures as it is for >>>architectures >>>that have significant design problems like X86. >> >>Fine, it's a 30% benefit to Alpha and MIPS, maybe it's 40% for x86... >> >>>>>The Cray T932 was the last 64 bit machine they built that I used. And it >>>>How many NPS does Crafty get on it? >>>about 7M. >>>And that was Cray Blitz, not Crafty. I have not tried to run Crafty on a Cray, >> >>7M per processor? How many processors did those Crays come with? 32? So Crazy >>Blitz was searching 224M NPS? I stand corrected, the T932 is several times >>faster than any other processor ever made. > >No. 7M total as I said, spread over 32 processors (actually we only used 31 >on that machine so that one could be dedicated to handling interrupts and the >like to avoid unnecessary context switches). > >> >>>>>I did a branchless FirstOne() in asm a few weeks back here, just to test. >>>>>It used a cmov, and it wasn't slower than the one with a branch. If the >>>>On a Pentium III? >>>On a pentium IV. >>>Although I did test it on my PIII xeon box, so I guess the answer is "yes" to >>>the III as >>>well... >> >>You "guess"? I never said anything about cmovs being bad for the P4, so why do >>you keep talking about the P4? >> >>-Tom > >I ran it on both, as I said. I simply almost forgot that my 700's were PIII's >while my dual 2.8 is PIV's. I did the testing on both since I use both to >play chess and fiddle with assembly. > >Restated: I ran the branchless stuff on a PIII/700 xeon, and a PIV/2800 xeon. >It worked well on both. I "guess" it therefore works well on all PIII/PIV >processors, even though I only have xeons to test. The only difference is the cache -- Xeons have more cache than the desktop chips. (Plus Xeons support 36-bit addressing in the cache. I have been told that the desktop varieties do not.) -Matt
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