Author: Matthew Hull
Date: 14:16:36 03/01/04
Go up one level in this thread
On March 01, 2004 at 16:53:51, Gerd Isenberg wrote: >On March 01, 2004 at 16:24:16, Robert Hyatt wrote: > >>On March 01, 2004 at 15:15:11, Vincent Diepeveen wrote: >> >>>On March 01, 2004 at 14:24:50, Robert Hyatt wrote: >>> >>>>On March 01, 2004 at 14:20:41, Robert Hyatt wrote: >>>> >>>>>On March 01, 2004 at 13:59:25, Eugene Nalimov wrote: >>>>> >>>>>>On March 01, 2004 at 13:49:38, Eugene Nalimov wrote: >>>>>> >>>>>>>On March 01, 2004 at 12:05:17, Vincent Diepeveen wrote: >>>>>>> >>>>>>>>On February 29, 2004 at 23:38:31, Robert Hyatt wrote: >>>>>>>> >>>>>>>>[snip] >>>>>>>> >>>>>>>>You qualify the testresults as done for SPEC as INVALID and INCORRECT? >>>>>>>> >>>>>>>>YES or NO? >>>>>>>> >>>>>>>>[bla bla removed] >>>>>>> >>>>>>>Had you stopped to drink vodka every morning? >>>>>>> >>>>>>>Please answer only YES or NO. >>>>>>> >>>>>>>[bla bla removed] >>>>>> >>>>>>So, my previous post pointed that there are questions for which you cannot >>>>>>answer "YES or NO". >>>>>> >>>>>>And here is *official* SPEC data for 1.3GHz K7 and 1.5GHz Itanium2: >>>>>> >>>>>>http://www.spec.org/cpu2000/results/res2001q4/cpu2000-20011008-01018.html >>>>>>http://www.spec.org/cpu2000/results/res2004q1/cpu2000-20040126-02775.html >>>>>> >>>>>>Thanks, >>>>>>Eugene >>>>> >>>>> >>>>>Please do not confuse discussions with Vincent by supplying real data. Things >>>>>stay on a more equal footing if you just make up stuff and post it here. >>>>> >>>>><sarcasm off> >>>>> >>>>>:) >>>> >>>> >>>>For those that didn't look at the data, the 1.5ghz K7 compared to the 1.5ghz >>>>itanium shows a 50% faster speed on the Itanium. IE the K7 took 127 seconds to >>>>run the test, the Itanium took 80. >>>> >>>>Why 1.5ghz K7? Because Vincent was talking about "clock for clock" and Eugene >>>>chose to supply real data rather than barking up a hollow tree... >>> >>>Latest itanium compiler 1.5Ghz 6MB L3. Compiler used from 2004. >>> base score : 1241 >>>Note this is the HP compiler which hardly anyone uses. No one in government is. >>>They all use the way slower intel compiler. The supercomputers of the government >>>aren't HP ones. HP isn't delivering big enough systems. >>> >>>But even then. Let's compare this 6 instructions a cycle Itanium2 with crafty at >>>K7 a 32 bits doing 3 instructions a cycle max: >> >>Flap flap flap flap. Flappety flap. Flap. Flap. flap-flap-flap. >> >>No matter how much hand-flapping you do, you made the original statement. >>Eugene supplied data that showed that clock for clock, the Itanium was 50% >>faster with Crafty. Nothing more, nothing less. No flappety-flap either. >> >> >> >> >> >>> >>>http://www.spec.org/osg/cpu2000/results/res2003q2/cpu2000-20030505-02154.html >>>K7 at 2.2Ghz getting: 1324 >>> >>>So after concluding that itanium is hell of a lot slower than K7, we can look to >>>the IPC. >> >> >>flappety-flap. >> >>Who cares. You said something that was simply shown to be wrong. >> >> >>> >>>The 6 instructions a clock from the itanium2 @ 64 bits delivers : >>> 1241/1324 * 2.2Ghz/1.5Ghz = 37% faster speed >>> >>>So years of work at compiler still didn't improve much from my 33% statement >>>that the 4 instructions a clock 21264 1Ghz delivered a few years ago. >>> >>>So the move from 32 bits to 64 bits can not have contributed more than a few % >>>of speed to crafty. >>> >>>Best regards, >>>Vincent >> >>"can not have contributed -> flappety flap." >> >>One of these days, I will have access to an opteron where I can do a 32 bit and >>64 bit compile with _everything_ else constant. Then we will _really_ know what >>32 -> 64 bit gives. It will be more than "a few %". > >I'll hope it ;-) > >OTOH how do you distinguish the gain of using additional registers even for >32-bit ints, which may dramatically decrease stack bandwidth and the gain of >pure 64-bit processing. Other 32-bit architectures (PPC) with plenty of registers do not show dramatic difference over x86-32 at the same clock speed (I know, apples/oranges :)). However, somebody posted G3/G5 numbers not too long ago which seemed to indicate 64 bit improvment over 32-bit was very good on PPC.......IIRC. >Do you have an idea, by profiling or estimation, of the >ratio between the number of average executed 32-bit and 64-bit instructions >inside crafty's search and eval? > >With some dependent bitboard operations you may introduce more register stalls >and probably less densitity using all execution ressources in parallel within >one processor, where 32-bit could do two independent instructions in parallel. >(intel64 with HT is coming ;-) > >With shifts, specially with generalized, there is really a huge win. But with >store/load and simple logical/arithmetical instructions and bitscan the win >isn't that huge, considering sequentially preparing and traversing one single >bitboard inside a register. > >Cheers, >Gerd
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