Stefan Reinauer wrote:
- ron minnich email@example.com [030718 21:12]:
On Fri, 18 Jul 2003, Dave Ashley wrote:
What disadvantages does SPD have other than it is more complex? Wouldn't it let you then be able to correctly use any DDR module you want?
some SPD roms have incorrect information. You have to take care with SPD.
Does this happen if you buy cheap ram, or ram of a certain type? How can this kind of problem be avoided? I heard and read this a couple of times now, but (I think) it never happened to me 'til now
SPD only works if the RAM vendor properly programs the serial EEPROM. RAM is a commodity item and vendors churn out millions of modules a year. An assembly line can build thousands of modules per day. If there is a hickup on the procurement side (parts not showing up or late for assembly) an assembler may be forced to use a different part number that is in stock that is still compatible with the module pcb layout but does not have the same timing specs. Other times the SPD info is just programmed wrong and the only QC is based on the end user complaining about a problem. Another way that SPD breaks is by flaky software or SPD bus corruption that writes data to the SPD device on the RAM module. Don't be surprised by how much broken PC hardware gets sent off to market with fixes via BIOS and other still broken means.