user70866: I am new to mining and not actually mining Bitcoin right now but want to understand more about it.
I have Core 2 Quad Q9550 CPU at 2.83 Ghz. I am mining with cpuminer only right now. I am getting 20 h/s on each core so 80 h/s for 4 cores.
When I put -t 8 for 8 threads I get around 11 h/s. Since this CPU doesn't support more than 4 threads at a time. What would be faster? more threads or 4 threads? or just 2 threads?
Curious to learn.
EDIT: I feel setting cpuminer to 8 threads generates more h/s.

user75108: -t 6 threads should be the best setting, half of the L3 cache. Give it a try and let us know how it goes. Also, see what the developer of xmrig (cpuminer 'competitor') says about it:
xmrig commented on Aug 29, 2017
"...Also 6 threads per CPU/Node is optimal, because of 12 MB L3 cache, each thread required 2 MB cache for optimal performance, more threads less hashrate. So 12 threads is optimal anyway, just need separate it."

70866: <p>I am new to mining and not actually mining Bitcoin right now but want to understand more about it.</p>

<p>I have Core 2 Quad Q9550 CPU at 2.83 Ghz. I am mining with cpuminer only right now. I am getting 20 h/s on each core so 80 h/s for 4 cores.</p>

<p>When I put -t 8 for 8 threads I get around 11 h/s. Since this CPU doesn't support more than 4 threads at a time. What would be faster? more threads or 4 threads? or just 2 threads?</p>

<p>Curious to learn.</p>

<p>EDIT: I feel setting cpuminer to 8 threads generates more h/s.</p>
 75108: <p>-t 6 threads should be the best setting, half of the L3 cache. Give it a try and let us know how it goes. Also, see what the developer of xmrig (cpuminer 'competitor') says about it:</p>

<p>xmrig commented on Aug 29, 2017</p>

<p>"...Also 6 threads per CPU/Node is optimal, because of 12 MB L3 cache, each thread required 2 MB cache for optimal performance, more threads less hashrate. So 12 threads is optimal anyway, just need separate it."</p>
