If by HTT you mean HT link then no, its at auto which I think is 1000. Note: 3.1 wasnt even stable enough for 2 hours of prime95 so im at 3.0ghz (200*15) with stock voltage 12 hour stress stable..
It's been a while since I've overclocked an AMD system as it's not something that comes up very often (usually AMDs are reserved for the cheapest builds due to their price/performance and such builds don't have the means to overclock), but in the Socket 939 days, the HyperTransport speed could never exceed 2000, and was 2000 to start with (5x multiplier) so you had to cut it to 4x in order to achieve up to a 25% speed boost, 3x if you were going any further. Not unlike having to balance memory speeds with the memory multiplier.