You should replace that thing with something more modern. I had a 5000p chipset system someone gave me with dual quad cores and an assload of ram.
The shitty box idled over 400W. I went as far as getting low power ram and the newest CPU it would support that also supported frequency and power scaling and it still used over 400W on idle.
This while I had a Xeon E5 box that was only a few years younger that uses more in the neighborhood of 50W on idle and utterly decimates the 5000 series box in CPU performance.
You're probably better of fetching some old Ryzen 1800x system of ebay for higher performance and leagues lower power consumption.
As for the raid, don't use it. Hardware raid has always been shit and in modern Linux and Windows is as good as completely depricated.