Optimizing interface speed

In the canned FrontPanel application I see a setting in Preferences for “Wire Update Rate” with values 25/100/200 ms. I’m doing all my work using the DLL instead. Is there an equivalent function in the API? Are these three values the only settings available?

My best case timing between two successive SetWireInValue/UpdateWireIn pairs is about 2.5 ms. Of course Windows jumps in every once in a while to make it a lot longer. Maybe this is the best I can do given the USB overhead (without using Pipes)?

Thanks.