Came across someone with a Extreme 4 MB and said his comp locked up every few minutes when his Logitech equipment was plugged into the USB3 ports.
Bingo finally found my problem - it is a driver conflict with USB3 and Logitech wtf - well I'm guessing its a driver conflict... I've a G19 and G35 that were plugged into the USB3 ports. Every-time I put them back in it plays up...
Surely they tested this MB with Logitech? Its caused me a few months of headache finding this. But hey I learned a lot along the way fault finding
Thanks to Izord
x79 Extreme4 freezes when USB 3 is plugged in.