Thanks. I upped TRFC to 58 and left everything else same at 4.356 and so far 10 linx passed @ 6.6Gb no problem. :)
Will try your suggestions if Linx freezes again.
I have tons of fans in my case ( 6 intake, 4 exhaust, 3 on cpu heatsink ), you think I can get by with just removing the Gigabyte cover?