Actually, my P5E-VM HDMI board had only 5 BIOS updates, and the only one that supposedly "supports" this CPU is a beta one with a whole bunch of other issues... which made me go back down to the one that did not support the CPU to begin with.
It seems to me... up until this point, like it's the board's limit rather than the chip's. Most X38/X48 boards are reporting 425-440 FSB walls, most P35 boards are reporting 450-460 FSB walls, and... most 780i boards are reporting 470-475 FSB walls. Coincidence?