MHz x Multipler: 200 x 17
Voltages can only be coarse adjusted (+50 Mv) on the CPU. Set to +150 Mv
Temperature of CPU during idle: around 50 C or slightly above.
Memory Ratio: Default (OCZ Memory of Champions DDR2800 [it overclocks horribly though])
Am I losing performance because I can't adjust the HT speed?
At 3.4GHz you are doing just dandy - the CPU is not holding back the GTX260.
The M3A78 is not a super-OC'er (if it's the model I'm thinking) --- on a typical AMD mobo with a 940BE, 3.4GHz/stock volts and decent power regulation you should idle at 33-34c and at load 44-45c.
You should not have to jack the volts to get that extra 400MHz.
As long as the HT is faster than you RAM speed you are fine. You should be able to increase the IMC/NB to 2200MHz (if not 2400MHz) for a little bump in performance.