Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!decwrl!atha!aupair.cs.athabascau.ca!rwa From: rwa@cs.athabascau.ca (Ross Alexander) Newsgroups: comp.arch Subject: Re: Compilers and efficiency Message-ID: Date: 13 May 91 16:15:23 GMT References: <9782@mentor.cc.purdue.edu> <653@ctycal.UUCP> <28297C23.6984@tct.com> <12216@mentor.cc.purdue.edu> Organization: Athabasca University Lines: 42 hrubin@pop.stat.purdue.edu (Herman Rubin) writes: >In article , rwa@cs.athabascau.ca (Ross Alexander) writes: >> hrubin@pop.stat.purdue.edu (Herman Rubin) writes: >> [much chat about whether Herman's apps are typical elided] >> >How much of the driving public uses the low gears of automatic transmissions? >> >> All of them, Herman. Whenever they accelerate from a stop. That's >> what an automatic transmission is for. >To clarify, I meant the specific ability to place the transmission in low gears. But the auto transmission knows when to do that for you. Some poor underpaid mechanical engineer spent years designing an analogue (fluid) computer that monitors engine speed, accelerator position, drive wheel speed, and torques and then selects a gear ratio with a view to optomizing fuel economy, engine wear, and ghods know what else. They are remarkably robust (mine currently has 275,000 km without any failures) and maintenance-free. Using one allows the operator to concentrate on an appropriate problem domain - keeping the vehicle out of the ditch. Why are you so d*mned eager to second guess this mechanism, and divert your attention from the thing that, compared to the machinery, you do well (guidance)? BTW, I don't accept the `snow hypothesis'; with proper tires, second gear starts to prevent slippage are redundant (and besides, they're hard on the engine - low speed/high torque (lugging) strains the crankshaft and its bearings). All these arguements can be moved back into the computer architecture discussion with remarkably little rephrasing, I might add. >Current computer hardware can do anything,assuming sufficient external storage, >but not efficiently. Similarly with software. I can only wonder that, if they're inefficient, why are they so much faster and cheaper that they used to be? What the heck do you mean by `efficient'? Obviously some new use of the word I was previously unaquainted with (apologies to Arthur Dent). -- Ross Alexander rwa@cs.athabascau.ca (403) 675 6311 ve6pdq `You were s'posed to laugh!' -- Zippy