The memory module specifications, developed by the JEDEC committee, please log in to http://www.jedec.org/ get more information? SPD is SERIAL PRESENCE DETECT abbreviation, in Chinese means the existence of serial test module. that is mentioned above by the IIC serial interface EEPROM on the memory slot of the module checks the existence of information. In this case, module related information shall be recorded in the EEPROM. Customarily, we Fengyun EEPROM IC called the SPD. But sometimes there is an error message read, say, some people find that their DIMM 2007 production date turned out to be 88 weeks, significantly, only 52 weeks a year it is not the software tools sucks? JEDEC standard given, in part, depending on the module? type defined, in part, manufacturers own definition, this part can not fill even so, a considerable part of the data is uncertain, or even not defined, then access the content of these EEPROM, it may explain the error. we look at all concerned about the data to see where they are in Figure 3 byte 03 ~ 06, there is byte 13, these data mean, one-sided 8-chip memory, the capacity of single-chip 256Mbit, so you can figure out?? This is the root of the memory of a total of 256MB. SPD byte 18 in the module can be given in this work the CL value. See byte 12h, the value 0Ch, meaning it can support CL = 2.5, 2 species. in front of byte 09 frequencies, it must be the maximum that is working in the CL on CL = 3, while working in the CL = 2, frequency is how much? to check byte 23, which in Figure 3 byte 17h, the value is 75h, that is 7.5ns, corresponding to 133MHz SPD information is not information, but read the chipset in the message that is another story.. If you read the old version of the software with the new value read is not the same, please a new version shall prevail, because the author may not have the software update to the new chipset release. chipset development speed faster than the JEDEC standard more:) about a fun thing, some of the IC is used to support DIMM PC133, but PC100 is the content of the SPD, which occurred mainly in companies like IBM, which is why? Some products, such as TP600E not Support PC133 and support PC100, but SODIMM suppliers may only be taken? to the PC133 IC, taking into account the IC is compatible with PC100, then, the SPD content written PC100, with the sale of accessories for the factory to avoid confusing users.