28 Apr
2009
28 Apr
'09
5:27 a.m.
On 27/04/2009 11:29, Bulat Ziganshin wrote:
Hello Simon,
Monday, April 27, 2009, 2:13:26 PM, you wrote:
This is a very strange result: the user time should not *decrease*, but rather should stay the same or increase a bit when adding cores. If
ability to run two threads simultaneous may increase performance in some scenarios. one example is consumer+producer threads. with 2 OS threads all produced data are consumed immediately, so we live inside L2 cache. with 1 OS thread produced data overflow the cache before threads are switched, making execution much slower
Yes, good point. Though I'd be surprised if that was happening here. Cheers, Simon