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Quickr 8.2.0.9 + Domino 8.5.1FP1 = Stable!
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Tue, Jun 22nd 2010 52
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Multithreading can be cores times slower or cores times faster than single threading
I added multithreading capability to the Siipi speedtest tool, and it showed surprising results: Looping got almost (number of cores) times faster, but allocating memory got almost (number of cores) times slower!
Here's the test with the first part using 4 cores, and 2nd part using 1 core (as before):
Speedtest 1.1 (c) 2009 Siipi
Counting 10 billion floating points using 4 cores...
thread 1 begin=25000.000000
thread 2 begin=50000.000000
Main loop begin=0.000000
thread 3 begin=75000.000000
thread 3 loop ended at 100000.000003.
thread 2 loop ended at 75000.000003.
thread 1 loop ended at 50000.000007.
Main loop Done. i=2500000050, n=25000.000009, time=4.390000s.
Creating and deleting 1 billion class objects using 1 cores...
Main loop Done. i=100000000, time=13.313000s.
Total time=17.703000s.
Now the same test with both parts using 4 cores:
Speedtest 1.1 (c) 2009 Siipi
Counting 10 billion floating points using 4 cores...
thread 1 begin=25000.000000
thread 2 begin=50000.000000
Main loop begin=0.000000
thread 3 begin=75000.000000
thread 3 loop ended at 100000.000003.
thread 1 loop ended at 50000.000007.
thread 2 loop ended at 75000.000003.
Main loop Done. i=2500000050, n=25000.000009, time=6.312000s.
Creating and deleting 1 billion class objects using 4 cores...
thread 1 begin=25000000
thread 2 begin=50000000
thread 3 begin=75000000
Main loop Done. i=25000000, time=66.188000s.
Total time=72.500000s.
As reference the original test, using no multithreading:
Speedtest 1.0 © 2008 Siipi
Counting 10 billion floating points...
Done. i=1410063201, n=100000.000003, time=15.078000s.
Creating and deleting 1 billion class objects...
Done. i=100000000, time=12.890000s.
Total time=27.968000s.
---------------------
http://siipi.com/public/mika.nsf/blogs/32C5E4BE99467B02C225768D006F8AAE
Dec 15, 2009
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