Crazy slow file transfers and folder browsing

[CatMan]

Hello,

I get very slow file transfers and folder browsing, often the server simply times out.
I recently bought an intel nic card (PCIE) 82572EI gigabit to use.

Build:FreeNAS-9.1.1-RELEASE-x64 (a752d35)
MB: MSI 790fx-gd70
(Patriot sector 5) 8gb dd53 ram
AMD Phenom(tm) II X4 955 Processor (black edition)

Using ZFS:
3x WD green 2tb in a raidz
2x samsung f4 2tb in a raid 1

Both sets are very very slow


Thank you!