Concurrency and program speed

[Joseph Rushton Wakeling]

On 02/28/2013 04:03 PM, Sean Kelly wrote:
> Does the laptop really have 4 cores or is it 2 cores with hyperthreading?  My guess is the latter, and that will contribute to the timing you're seeing.

You're absolutely right.  So I think I know my own laptop ... :-P

> Do larger jobs show a better or worse speedup?

Increasing the number of threads generally seems to make for a worse ratio, 
which I guess is explained by thread latency.

Thanks for the assistance!