Re: stream

From: John W. Kupec (kupec@agouron.com)
Date: Fri Oct 28 1994 - 15:08:29 CDT


On Oct 28, 3:32pm, John D. McCalpin wrote:
> Subject: Re: stream
> On Oct 28, 12:05pm, John W. Kupec wrote:
> > Having problems here. I've tried various f77 incantations &
> > get "Segmentation fault" under IRIX 6.0 and IRIX 5.2 (R4400).

Sure enough, stacksize was 64Mb. Here's the results after compiling
"f77 -mips4 -O3 stream_d.f -o stream_d" on Power Challenge-L, IRIX 6.0,
1GB, 2-way interleaved memory:

--------------------------------------
 Double precision appears to have 16 digits of accuracy
 Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
 Timing calibration ; time = 118.6243979260325 hundredths of a second
 Increase the size of the arrays if this is <30
  and your clock precision is =<1/100 second
 ---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 130.9830 0.4904 0.4886 0.4991
Scaling : 131.8875 0.4871 0.4853 0.4921
Summing : 129.2836 0.7464 0.7426 0.7659
SAXPYing : 129.0843 0.7448 0.7437 0.7462
 Sum of a is : 2.3066015625918735E+18
 Sum of b is : 4.6132031248564384E+17
 Sum of c is : 6.1509375001412557E+17

real 27.26
user 25.37
sys 1.26

There is no -O4 under IRIX 6.0.

Here are the results I obtained with "f77 -mips2 -O3 -non_shared"
on an Indigo 2, IRIX 5.2, 150Mhz R4400 CPU, 128MB memory:

--------------------------------------
 Double precision appears to have 16 digits of accuracy
 Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
 Timing calibration ; time = 309.9999904632568 hundredths of a second
 Increase the size of the arrays if this is <30
  and your clock precision is =<1/100 second
 ---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 59.8131 1.1270 1.0700 1.3300
Scaling : 57.1427 1.2077 1.1200 1.4000
Summing : 61.1465 1.7146 1.5700 2.0100
SAXPYing : 67.1329 1.5382 1.4300 1.8700
 Sum of a is : 2.3066015623519370E+18
 Sum of b is : 4.6132031251484826E+17
 Sum of c is : 6.1509374999898381E+17

real 1:02.47
user 54.58
sys 5.66

Would you mind providing comparisions to other machines?

Thanks



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