Four threads ? So it's better to use 4 normal threads than 3 + dualmine ? [heart broken]
If that's what you say, so it's another proof the dual mine is useless outside the very rare case of a 2M-cache dual core cpu.
Yes, indeed, he is right:If that's what you say, so it's another proof the dual mine is useless outside the very rare case of a 2M-cache dual core cpu.
3T => 58 H/s
3T + helper => 64 H/s
4T => 70 H/s
And that despite Deneb has only 6 MB L3 cache.
But I forgot the special cache architecture of AMD systems. Intel systems have inclusive caches. So the size of the L3 cache is the maximum cacheable size, because the data in L2 and L1 are just subsets of a copy. AMD systems instead have exclusive caches, where no data is ever stored in L2 and L3 at the same time. That's why you can add L2 and L3 cache size. Deneb has 4x 512 KB L2. Together with the 6 MB L3 you get 8 MB cache altogether; or room for 4 threads. 
But it still can be helpful for non-AES Intel CPUs with limited L3 (Lynnfield) or for Phenom II X6 to use the last two cores, as well
Still PhenomII X6 have better performance with 6T than 5T+helper, 153 vs 141.
What clock is your X4 running?