Was it always slow when you first tested or did this just started to be slow? There are many types of call trace errors, what your showing can point out to be IRQ hogging and you might want to remove any power management from the BIOS of the motherboard. Check that the firmware is updated on the RAID controller and the motherboard. Check to see if the RAID controller is not in a Write Thru state or that it is charging the built in battery device or doing a rebuild from a failed drive.