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Article #12167Analogies and Performance
From: Donald Lindsay
Date: Wed, 19 Jun 1991 00:15
Date: Wed, 19 Jun 1991 00:15
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1530 bytes
In article <2688@m1.cs.man.ac.uk> mshute@cs.man.ac.uk (Malcolm Shute) writes: >>If long legs are *it*, how come you can't run faster than my dog? >Does this mean that we should be measuring 'Leg-Complexity', not 'Leg'. What users measure is "end to end" speed. (That's the track's ends, not dogends... ) It is interesting to measure factors that contribute to speed, but there are lots of semantic pitfalls. For example, what does "length" mean if the leg is never straight? Measures depend on models, which are abstract. There are usually problems with abstractions (and with biological analogies). This is why simulated systems so often perform wonderfully well: they abstracted out something significant, such as cache misses, or DRAM refresh, or DMA contention .. or realistic coding practices. There's a very nice phrase in aerial photography. The photo-analyst draws deductions from the images: but if she actually goes to the site, she will learn the "ground truth". It can be an enlightening experience. -- Don D.C.Lindsay Carnegie Mellon Robotics Institute
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!zaphod.mps.ohio-state.edu!ub!galileo.cc.rochester.edu!rochester!pt.cs.cmu.edu!gandalf.cs.cmu.edu!lindsay From: lindsay@gandalf.cs.cmu.edu (Donald Lindsay) Newsgroups: comp.arch Subject: Analogies and Performance Message-ID: <13513@pt.cs.cmu.edu> Date: 19 Jun 91 00:15:16 GMT References: <2688@m1.cs.man.ac.uk> Organization: Carnegie Mellon Lines: 23