1) lower your buffers when recording....
this allows the computer to put more of it's resources into capturing the sound and reproducing it accurately - therefore giving you better latency

2) rasie your buffers when Mixing....
this allows the computer to put more of of it's resources on Plugins and the actual repsonse time when moving your faders up and down and making the calculations to trigger those changes back to you

3) REallocate more RAM to the program....
the RAM that is allocated at the default is really only enough to run MIDI and a few Audio tracks. DP3 works well with a preferred size of about 100-150 megs. Old versions of DP should not have such a high preferred size (DP2.7 worked best at 40megs)

4) check the control panel / or setup buffers of the Audio card in question..
the buffers settings of your Audio card also take a large portion of the processing power when you adjust the buffers of your card properly. Most Cards have their own settings - read the documentation of that particular card