"The CUV4X has almost the exact features of the P3V4X, with the exception of one less PCI slot and one less DIMM slot. Another noticeable difference between the two is the CUV4X uses VIA's new 694z northbridge. This new northbridge offers no performance gain, but is simply pin-pin compatible with VIAs integrated plans. This means we will more then likely see a PM133 based Asus board. Also the southbridge on the P3V4X is the 586b which allows for only two USB ports and no onboard audio."
FULL STORY @ VIAHARDWARE (http://www.viahardware.com/cuv4x.htm)