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Re: IDL time test with a PowerMac G4 [message #17333 is a reply to message #17330]

Fri, 08 October 1999 00:00

pford1955
Messages: 2
Registered: October 1999

Junior Member

In article <b13L3.5294
$cPf.197315584@news.telia.no>,
roy.hansen@triad.no (Roy E. Hansen) wrote:
> In article <gurman-
0410991751060001@barkochba.nascom.nasa.gov>,
> gurman@gsfc.nasa.gov (Joseph B. Gurman) wrote:
>
>> Running IDL 5.2 without any special
Velocity Engine (AltiVec) plugins
>> or other mods, a G4/450 running Mac OS 8.6
with 128 Mbyte of memory and a
>> 20 Gbyte Western Digital (stock) Ultra ATA
hard drive gets the following
>> results on time_test2:
>>
> snip - snip
>
>> 4.73333=Total Time,
0.096772401=Geometric mean, 23 tests.
>
> Running time_test2 on my P-II 400 laptop
produces the same total time
> (4.7300 seconds, see below). I though the new
G4 was a > 1 Gflops machine
> excellent for numerical stuff but, this small
comparison indicates that my standard
> PC is equally fast.... Is there something I am
missing here, or is'nt the new G4 as
> fantastic as announced? Well, to answer my
self - I fooled myself by studying the total
> time from time_test2. By studying test 20 in
time_test2 (forward and inverse 1D FFT)
> the test looks like this:
>
> G4/450: 20 0.150000 131072 point
forward plus inverse FFT
> G3/350: 20 0.300000 131072 point
forward plus inverse FFT
> Alpha500: 20 0.243165 131072 point
forward plus inverse FFT
> P-II 400: 20 0.550000 131072 point
forward plus inverse FFT
>
> So it may be that the G4 is a supercomputer
after all.....
>
> --RoyH

Yes, there is something that you are missing
here. In the introduction to the G4 test, it
states "without any special Velocity Engine
(AltiVec) plugins or other mods..." The Gflop
numbers are ONLY for AltiVec ready or enabled
applications. The G4 is only marginally faster in
floating point than the G3. It is faster than a
Pentium at the SAME CLOCK RATE, but Pentiums are
clocked faster. It is like saying MMX does not
add anything to graphics because the the program
does not use it.

Regards

Patrick Ford, MD
Baylor College of Medicine
pford@bcm.tmc.edu

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[Message index]

		Re: IDL time test with a PowerMac G4 By: gurman on Fri, 08 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: Patrick V. Ford on Fri, 08 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: pford1955 on Fri, 08 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: pford1955 on Fri, 08 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: Mark Hadfield on Fri, 08 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: Pavel Romashkin on Thu, 07 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: roy.hansen on Thu, 07 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: gurman on Thu, 07 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: mgs on Wed, 06 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: Pavel Romashkin on Wed, 06 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: m218003 on Wed, 06 October 1999 00:00
		Re: IDL time test with a PowerMac G4 By: Pavel Romashkin on Tue, 05 October 1999 00:00

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