There is more. it's just that the HT isnt balanced, keeps jumping up and down 2mhz every 5sec or so. hard to just go 50mhz above the speed you intend to bench, resulting in a crash. which is crap.
I think it'll do 6,5ghz. i booted it up with 4,5ghz NB @ 5,5ghz. had some issues, so lowered NB to make sure it wasnt that. but most likely 4.1+ will go easy on same clocks aswell.

Hope to improve the score this week, will try to arrange LN2 tomorrow for this week