It ought to be. Your processor is probably running at 100mhz FSB. Times that by 4 for Pentiums, and that gives you an effective FSB of 400. The memory is actually capable of 800mhz on an appropriate Pentium processor and motherboard. DDR400 = memory running at 200mhz, x 4 in a P4 system = 800mhz FSB.
As for an utility to show what the memory is capable of, I don't know.