Author: Angrim
Date: 10:49:46 08/25/03
Go up one level in this thread
On August 24, 2003 at 21:50:28, Robert Hyatt wrote: >On August 23, 2003 at 03:45:09, Johan de Koning wrote: > >>On August 22, 2003 at 10:45:11, Robert Hyatt wrote: >> >>>On August 22, 2003 at 02:53:06, Johan de Koning wrote: >>> >>>>On August 21, 2003 at 11:29:49, Robert Hyatt wrote: >>>> >>>>>On August 21, 2003 at 03:16:35, Johan de Koning wrote: >> >>[snip] >> >>>>>>Hence I dare to ask: 25% of what? >>>>> >>>>>NPS went _up_ by 25%+. So total engine speed. >>>>> >>>>>This was changed in Crafty version 9.16, which dates back many years. >>>> >>>>Whoah! This is *very* hard to believe. >>>>There must have been something severely wrong with 9.15 then (continuing chache >>>>trashing comes to mind, but that's just guessing). More likely, this number does >>>>not come from a clean comparison of copy/make versus make/unmake. >>> >>>The _only_ change made was to replace copy/make with make/unmake. Think about >>>the math. >> >>Thinking about the math is easy. Doing the math in order to get valid results is >>much harder since it requires facts to start with. >> >>> Copy/make copies 256 bytes+. Once _every_ node. On today's >>>hardware, my dual xeon 2.8, I search about 2.4M nodes per second. or about >>>400ns per node. Copying 256 bytes is certainly going to show up on the radar >>>in a significant way, when it gets done once every 400 ns. >> >>To start simple, at 2.4 MN/s the average node takes 833 ns, or 2333 cycles. >>That's a fact. :-) > >OK.. Fact #1. Your calculator is _broken_. :) > >Enter 1 / 2400000 and hit the = button. > > >You will get 417 nanoseconds. You are off by a factor of two, somehow. > I'd guess that he is taking into account that it is a dual cpu system. So 833 ns per node, but you can do two nodes at once. This seems reasonable to me. Angrim
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