What would be better suited for unraid and have better performance:

 

a X7SPA-HF-D525 or a X9SCM-F plus Intel Celeron G540? Price is comparable in Holland, but the X9SCM-combo gives more expansion options.

I have a faster processor on the X9SCM-F (a Xeon E3 1265Lv2), and i notice large difference in copy speed for example.

I copy from the same source PC, to the same type of cache drive: hitachi 1 TB.

Atom: 72 mbps as long as it can be cached, after the ram is full, 38-40 MB/sec

X9SCM: 70-80 MB/s not depending on the memory buffer it seems.

 

Always leave room for growth.

Even the Celeron would blow that Atom processor out of the water. Unless you are specifically looking for very low power go for the X9SCM.