Is java7 faster than java6?

 

There was recent discussion about Java7 performance for numerical calculations. Few people saw some 20-40% improvement for java7, compare to Java6. This simple script which can be executed in jhepwork shows no such improvement. Run this code above (here I'm using 2 cores) and see it yourself:

#########################################################################################################
from cern.colt.matrix        import *
from edu.emory.mathcs.utils  import ConcurrencyUtils
import time

# do some calculations on DenseDoubleMatrix2D
def process(M):
       M.cardinality()
       M.dctColumns(0)
       M.dctRows(0)
       M.dct2(0)  
       M.dht2()
       M.dhtColumns()
       M.dhtRows() 
       M.dst2(0)
       M.dstColumns(0)
       M.dstRows(0)
       M.vectorize()
       M.zSum()
       M.idct2(0)

Ncores=2
print " benchmarks of DenseDoubleMatrix2D for "+str(Ncores)+"  CPU core. Wait!"
ConcurrencyUtils.setNumberOfThreads(Ncores)
start = time.clock()
M=tdouble.DoubleFactory2D.dense.random(2000, 2000) # random matrix
process(M)
print ' Multiple CPU time (s)=',time.clock()-start

###########################################################################

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Additional uncaught exception thrown while handling exception.

Original

PDOException: SQLSTATE[HY000]: General error: 1364 Field 'aid' doesn't have a default value: INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => Is java7 faster than java6? [:db_insert_placeholder_1] => node/11 [:db_insert_placeholder_2] => [:db_insert_placeholder_3] => 50.16.52.237 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => gPHWs6ueqo2t76vepf8qU1BGM2XxX4IrLAFBkhvPBvM [:db_insert_placeholder_6] => 198 [:db_insert_placeholder_7] => 1481155507 ) in statistics_exit() (line 93 of /home1/jworkorg/public_html/main/modules/statistics/statistics.module).

Additional

PDOException: SQLSTATE[HY000]: General error: 1364 Field 'wid' doesn't have a default value: INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] => 0 [:db_insert_placeholder_1] => php [:db_insert_placeholder_2] => %type: !message in %function (line %line of %file). [:db_insert_placeholder_3] => a:6:{s:5:"%type";s:12:"PDOException";s:8:"!message";s:809:"SQLSTATE[HY000]: General error: 1364 Field 'aid' doesn't have a default value: INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => Is java7 faster than java6? [:db_insert_placeholder_1] => node/11 [:db_insert_placeholder_2] => [:db_insert_placeholder_3] => 50.16.52.237 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => gPHWs6ueqo2t76vepf8qU1BGM2XxX4IrLAFBkhvPBvM [:db_insert_placeholder_6] => 198 [:db_insert_placeholder_7] => 1481155507 ) ";s:9:"%function";s:17:"statistics_exit()";s:5:"%file";s:69:"/home1/jworkorg/public_html/main/modules/statistics/statistics.module";s:5:"%line";i:93;s:14:"severity_level";i:3;} [:db_insert_placeholder_4] => 3 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => http://jwork.org/main/?q=node/11 [:db_insert_placeholder_7] => [:db_insert_placeholder_8] => 50.16.52.237 [:db_insert_placeholder_9] => 1481155508 ) in dblog_watchdog() (line 160 of /home1/jworkorg/public_html/main/modules/dblog/dblog.module).