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View Full Version : what is Lock Contention?


blue&whiteman
May 13, 2004, 09:30 PM
this is one of the tests xbench does on the cpu. my G4/500 cpu (a 7410 ver. 1.4) almost doubles the score of a sawtooth 500 (7400 ver. 2.8).

so what is lock contention? in all the other cpu tests the 2 were almost totally equal.

how can 2 cpu's of the same type and speed differ so much? is the 7410 really that much better at some tasks over the 7400?

my cpu in blue

blue&whiteman
May 14, 2004, 07:48 AM
I have looked all over the internet and still cannot find an answer. most of the results I found with the term lock contention seemed to be sun miro oriented though.

there must be someone here that knows.

wrldwzrd89
May 14, 2004, 08:32 AM
I have looked all over the internet and still cannot find an answer. most of the results I found with the term lock contention seemed to be sun miro oriented though.

there must be someone here that knows.
I looked at wikipedia.org and determined from the article on locks in computer science and the article on contention that the test measures how well a multiprocessor system can cope with two threads competing for a lock on the same resource.

blue&whiteman
May 14, 2004, 09:03 AM
I looked at wikipedia.org and determined from the article on locks in computer science and the article on contention that the test measures how well a multiprocessor system can cope with two threads competing for a lock on the same resource.

my system and the one it beat are both single G4's though..

hmm. this seems to be a hard one. maybe I will email the maker of xbench.

wrldwzrd89
May 14, 2004, 09:09 AM
my system and the one it beat are both single G4's though..

hmm. this seems to be a hard one. maybe I will email the maker of xbench.
Lock contention is a threading test - it works on single-processor Macs like your G4, but it was designed to test multi-processor Macs. Since all Mac OS X systems are threaded, regardless of how many processors they have, there isn't anything wrong I can see with your results.