I have desktop in which I installed HP SmartArray P400 controller with two HP DF0146B8052 hard drives. I made RAID0 logical volume from them, but I am getting 20MB/s write speed and ~140-120MB/s read speed. Also there is quite low scatter for benchmark results (I am getting quite nice line) and it looks like controller is "capping" my speeds. I tried reseting controllers configuration and I haven't found any settings in HP ACU (Array Configuration Utility) to help me.
I am using Windows 7 Ultimate and M4A78 board
Does anyone have ideas what could be wrong? Also I am attaching diagnostic results.