Thanks for the info. I changed the cache page size to 16K and a significant improvement has followed.
But for you second suggestion with the element size of 256. I simply cannot bind a LUN with a -elsz 256 .
When I run the bind command the have the following error:
Too few or invalid command line parameters: -elsz
Valid usable-size for drive type: 128
Otherwise I'm actually using 4 RaidGroups of 7+1 drives accros my 3 DAE and my 35 Disks. (3 HS)
Running tests are quite good 300MB/s W so far