MR816 and Sonnet FW800 PCI-e and Performance


Is there anyone who can confirm that the MR816csx times three and a Sonnet FW800 PCI-e is a working solution?
It works over here, but I am not satisfied with the performance at the moment.

Furthermore, I like to track 24inputs (synths) and use a lot of plugins (f.e. the drop which is quiet CPU heavy). It seems that my i2600 isn’t capable of that anymore (in realtime)

My system:
i2600 (non-k version)
8gb corsair ddr3
1 ssd and 2 hdd’s
edirol um880 usb
nektar p6 panorama usb
2 * uad2 duo.
Cubase 8 pro and other daw’s.
Windows 8.1 pro
Sonnet 800 FW

Will a i7 5820K (overclocked) or 5930K based system suit my needs?
Or do I have to upgrade to another interface like RME Raydat or HDSP?

Thanks in advance.