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Why does the power on process take longer time for KR7A system? Is there any memory compatibility issue? (KR7A and other KT266A chipset board)

<Symptom> Why does the power on process take longer time for KR7A system? Is there any memory compatibility issue? (KR7A and other KT266A chipset board) <Explanation> While KR7A system is powered on, the BIOS will do a memory checking process and it takes about 5~15 seconds, then continue POST sequence. According to the datasheet of VIA KT266A chipset (Revision 2.1, September 14, 2001), x4 bit memory chip is not supported. Page 3, Advanced High-Performance SDR/DDR DRAM Controller Supports 8 banks up to 4 GB DRAMs (512Mb x8/x16 DRAM technology) for registered SDR/DDR modules Supports 6 banks up to 3 GB DRAMs (512Mb x8/x16 DRAM technology) for unbuffered SDR/DDR modules Most of the DDR memory 1G modules available now consist of 64Mx4 chip, which can't be used on KR7A board. Before purchasing the memory module, we suggest users carefully check out the memory specification, which should be provided by memory module vendor. The following picture illustrates a DDR 1G module made by 64Mx4 chip and special technology- stacking two memory chip together. This kind of memory can't be supported by VIA KT266A chipset. The maximum DDR memory support of KR7A is about 3.5G rather than 4G. This limitation is caused by PC architecture and the missing 0.5G memory address is reserved for PCI I/O space, AGP aperture mapping space and other onboard device I/O space, so, although the KT266A datasheet exclaims the memory support is up to 4GB, actually the system only use about 3.5GB with four 1G DDR memories installed. In another word, BIOS and operation system will report about 3.5GB only.