cost of Java "assert" when disabled?

[Srinivas Ramakrishna]

A Java language newbie question:

Does anyone have any ballpark numbers on the cost (and its scaling) of
peppering assert's in your Java code, but with asserts disabled (-da) ?
In other words, is the disabled cost so vanishingly small that we need not
think twice when using them, or should one be
careful because the cost is non-negligible and can affect (bytecode)
footprint or rutime performace even when switched off?

thanks for any advice.
-- ramki