The man page states the CM5 timers have microsecond precision.
I tried a few other vector lengths, and the results are remarkably
consistent. The runs were made when I had the partition virtually to myself.
I have had varying results timing operations that involved communications,
but not these. Would like to see results from some other CM5 sites,
but Australia only has 32 PN machines.
Rob
Compiled with NO optimization: cmf -implicit_none stream_d.fcm
STREAM: Measure memory transfer rates in MB/s
for simple computational kernels in Fortran
CALL CMF_describe_array(a)
desc_or_obj_kind : array argument
element_type : double float
home : cm
user_rank : 1
axes_extents : 12800000
axes_layout_maps : 1
element_size : 8
Array geometry id: 0x93b28
Rank: 1
Number of elements: 12800000
Extents: [12800000]
Machine geometry id: 0x93ac8, rank: 1, column major
Machine geometry elements: 12800000
Overall subgrid size: 200000
Axis 0:
Extent: 12800000 (64 physical x 200000 subgrid)
Off-chip: 6 bits, mask = 0x3f
Subgrid: length = 200000, axis-increment = 1
CM5 with partition of 16 processors ( 64 vector units )
--------------------------------------
Double precision appears to have 16 digits of accuracy
Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
Vector length = 12800000
Timing calibration: Time = 7.229106060606060 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: 4885.82465 0.04206 0.04192 0.04332
Scaling : 4894.24551 0.04185 0.04185 0.04187
Summing : 5129.65827 0.05996 0.05989 0.06128
SAXPYing : 5129.20148 0.05997 0.05989 0.06130
===================================================================
Compiled with Optimization: cmf -O -implicit_none stream_d.fcm
STREAM: Measure memory transfer rates in MB/s
for simple computational kernels in Fortran
CALL CMF_describe_array(a)
desc_or_obj_kind : array argument
element_type : double float
home : cm
user_rank : 1
axes_extents : 6400000
axes_layout_maps : 1
element_size : 8
Array geometry id: 0x93c10
Rank: 1
Number of elements: 6400000
Extents: [6400000]
Machine geometry id: 0x93bb0, rank: 1, column major
Machine geometry elements: 6400000
Overall subgrid size: 100000
Axis 0:
Extent: 6400000 (64 physical x 100000 subgrid)
Off-chip: 6 bits, mask = 0x3f
Subgrid: length = 100000, axis-increment = 1
CM5 with partition of 16 processors ( 64 vector units )
--------------------------------------
Double precision appears to have 16 digits of accuracy
Assuming 8 bytes per DOUBLEPRECISION word
--------------------------------------
Vector length = 6400000
Timing calibration: Time = 3.616887878787879 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: 4882.29863 0.02098 0.02097 0.02101
Scaling : 4894.68150 0.02092 0.02092 0.02093
Summing : 7333.00445 0.02095 0.02095 0.02096
SAXPYing : 7335.86990 0.02094 0.02094 0.02099
This archive was generated by hypermail 2b29 : Tue Apr 18 2000 - 05:23:03 CDT