Author: George Sobala
Date: 14:02:48 09/03/02
Go up one level in this thread
I have no axe to grind with either side. In fact, through these discussions Robert Hyatt's explanations seem considered and rational, whilst Vincent seems to be going off the deep end. HOWEVER there is absolutely NO WAY that the following table is genuine raw data. The times in seconds are all far too-perfect divisions of the time taken by one processor. Real life does not spew out such perfection. Let me explain. E.g. in pos 1, for 4 processors note that 2830/832 is 3.4014423. This is really close to 3.4 - so much so that 2830/3.4 is 832-plus-a-bit. Work your way down the columns and you will see that the time for x processors in seconds is far far far too often just what you would get if you divided the 1-processor time by a divisor with one decimal place (e.g. 3.4, 3.6, 3.7 etc) - not a second or two more or a second or two less. Why shouldn't we frequently see times that would be the result of 2-decimal place divisors, such as 3.43 or 3.58? Conclusion: this is inescapably NOT raw data. (And if you want "proof", Dr Hyatt, take it to a statistician at your university.) However, that does not automatically mean that it is invented or spurious. For example, the original data in seconds could have been recorded, divided out and rounded down to produce ratios accurate to one decimal place, and then (with this raw data lost or mislaid) for the purpose of the publication a "back-calculation" may have been done using the rounded divisors. On September 03, 2002 at 16:12:13, Robert Hyatt wrote: >Here it is: > > >First, times in seconds: > >pos 1 2 4 8 16 >1 2,830 1,415 832 435 311 >2 2,849 1,424 791 438 274 >3 3,274 1,637 884 467 239 >4 2,308 1,154 591 349 208 >5 1,584 792 440 243 178 >6 4,294 2,147 1,160 670 452 >7 1,888 993 524 273 187 >8 7,275 3,637 1,966 1,039 680 >9 3,940 1,970 1,094 635 398 >10 2,431 1,215 639 333 187 >11 3,062 1,531 827 425 247 >12 2,518 1,325 662 364 219 >13 2,131 1,121 560 313 192 >14 1,871 935 534 296 191 >15 2,648 1,324 715 378 243 >16 2,347 1,235 601 321 182 >17 4,884 2,872 1,878 1,085 814 >18 646 358 222 124 84 >19 2,983 1,491 785 426 226 >20 7,473 3,736 1,916 1,083 530 >21 3,626 1,813 906 489 237 >22 2,560 1,347 691 412 264 >23 2,039 1,019 536 323 206 >24 2,563 1,281 657 337 178 >
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