Our PChallenge bandwidth results

From: weyrich@compt.chemie.uni-konstanz.de
Date: Fri Jan 27 1995 - 12:25:05 CST


Dear Dr. McCalpin,

With great interest I still follow the messages you distribute
about the bandwidth of the PChallenge vs. the J90, now with more
than one processor.

Attached you find the file-captured output of cstream.c and
stream_d.f, compiled with different options, on our PChallenge --
obviously utilising only one processor and with a disaster when
switching on the f77 optimiser. Could you comment on the results?
Do you know how to avoid the f77 disaster? What is the meaning
of the error messages?

I would furthermore be very much interested in receiving advice
from you how to parallelise your benchmark for the PChallenge.
Could you even send me the sources?

In the meantime I will sort and comment some other stream output
tables for you.

Hope to hear from you soon.

Sincerely yours,

Wolf Weyrich.

*****************************************************************

cc -O0 -o cstream cstream.c -lm
"cstream.c", line 69: warning(1552): variable "c" was set but never used
  static real a[N],b[N],c[N];
                        ^

WARNING 84: /usr/lib64/mips4/libm.so is not used for resolving any symbol.
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):cstream
Timing calibration ; time = 600.00 usec.
Increase the size of the arrays if this is < 300
and your clock precision is =< 1/100 second.
---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 55.869 305.074 300.000 320.000
Scaling : 47.888 355.035 350.000 360.000
Summing : 62.853 417.145 400.000 440.000
SAXPYing : 57.139 448.085 440.000 460.000
iris%weyrich(/home1/ch/weyrich):cc -O1 -o cstream cstream.c -lm
"cstream.c", line 69: warning(1552): variable "c" was set but never used
  static real a[N],b[N],c[N];
                        ^

WARNING 84: /usr/lib64/mips4/libm.so is not used for resolving any symbol.
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):cstream
Timing calibration ; time = 440.00 usec.
Increase the size of the arrays if this is < 300
and your clock precision is =< 1/100 second.
---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 79.813 221.201 210.000 240.000
Scaling : 64.465 263.078 260.000 280.000
Summing : 81.101 315.071 310.000 330.000
SAXPYing : 78.566 332.054 320.000 340.000
iris%weyrich(/home1/ch/weyrich):cc -O2 -o cstream cstream.c -lm
"cstream.c", line 69: warning(1552): variable "c" was set but never used
  static real a[N],b[N],c[N];
                        ^

WARNING 84: /usr/lib64/mips4/libm.so is not used for resolving any symbol.
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):cstream
Timing calibration ; time = 340.00 usec.
Increase the size of the arrays if this is < 300
and your clock precision is =< 1/100 second.
---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 128.929 135.241 130.000 150.000
Scaling : 128.929 135.093 130.000 140.000
Summing : 139.674 187.216 180.000 210.000
SAXPYing : 139.674 196.265 180.000 220.000
iris%weyrich(/home1/ch/weyrich):cc -O3 -o cstream cstream.c -lm
"cstream.c", line 69: warning(1552): variable "c" was set but never used
  static real a[N],b[N],c[N];
                        ^

WARNING 84: /usr/lib64/mips4/libm.so is not used for resolving any symbol.
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):cstream
Timing calibration ; time = 320.00 usec.
Increase the size of the arrays if this is < 300
and your clock precision is =< 1/100 second.
---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 139.674 127.161 120.000 140.000
Scaling : 139.674 123.085 120.000 130.000
Summing : 139.674 186.172 180.000 200.000
SAXPYing : 139.674 189.130 180.000 200.000
iris%weyrich(/home1/ch/weyrich):cc -O4 -o cstream cstream.c -lm
cc ERROR parsing -O4: unknown flag
iris%weyrich(/home1/ch/weyrich):f77 -O0 -o stream_d stream_d.f
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):stream_d
--------------------------------------
 Double precision appears to have 16 digits of accuracy
 Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
 Timing calibration ; time = 119.3735010921955 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: 50.6767 0.6370 0.6315 0.6459
Scaling : 47.4971 0.6774 0.6737 0.6840
Summing : 57.3619 0.8447 0.8368 0.8588
SAXPYing : 57.0896 0.8494 0.8408 0.8618
iris%weyrich(/home1/ch/weyrich):f77 -O1 -o stream_d stream_d.f
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):stream_d
--------------------------------------
 Double precision appears to have 16 digits of accuracy
 Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
 Timing calibration ; time = 2.9999762773513794E-03 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:********** 0.0000 0.0000 0.0000
Scaling :********** 0.0000 0.0000 0.0000
Summing :********** 0.0000 0.0000 0.0000
SAXPYing :********** 0.0000 0.0000 0.0000
iris%weyrich(/home1/ch/weyrich):f77 -O2 -o stream_d stream_d.f
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):stream_d
--------------------------------------
 Double precision appears to have 16 digits of accuracy
 Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
 Timing calibration ; time = 2.8999522328376770E-03 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:********** 0.0000 0.0000 0.0000
Scaling :********** 0.0000 0.0000 0.0000
Summing :********** 0.0000 0.0000 0.0000
SAXPYing :********** 0.0000 0.0000 0.0000
iris%weyrich(/home1/ch/weyrich):f77 -O3 -o stream_d stream_d.f
WARNING 85: definition of qlogb in /usr/lib64/mips4/libm.so preempts that definition in /usr/lib64/mips4/libc.so.
iris%weyrich(/home1/ch/weyrich):stream_d
--------------------------------------
 Double precision appears to have 16 digits of accuracy
 Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
 Timing calibration ; time = 2.9999762773513794E-03 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:********** 0.0000 0.0000 0.0000
Scaling :********** 0.0000 0.0000 0.0000
Summing :********** 0.0000 0.0000 0.0000
SAXPYing :********** 0.0000 0.0000 0.0000
iris%weyrich(/home1/ch/weyrich):f77 -O4 -o stream_d stream_d.f
f77 ERROR parsing -O4: unknown flag
iris%weyrich(/home1/ch/weyrich):cstream
Timing calibration ; time = 320.00 usec.
Increase the size of the arrays if this is < 300
and your clock precision is =< 1/100 second.
---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 139.674 126.174 120.000 140.000
Scaling : 139.674 124.177 120.000 140.000
Summing : 139.674 185.122 180.000 200.000
SAXPYing : 139.674 188.149 180.000 200.000
iris%weyrich(/home1/ch/weyrich):cstream
Timing calibration ; time = 310.00 usec.
Increase the size of the arrays if this is < 300
and your clock precision is =< 1/100 second.
---------------------------------------------------
Function Rate (MB/s) RMS time Min time Max time
Assignment: 139.674 128.141 120.000 140.000
Scaling : 139.674 125.180 120.000 140.000
Summing : 139.674 185.122 180.000 200.000
SAXPYing : 139.674 186.064 180.000 190.000
iris%weyrich(/home1/ch/weyrich):
*****************************************************************



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