Messages in this thread | | | Subject | Re: AMD MP, SMP, Tyan 2466 | From | Edward Tandi <> | Date | 26 Jun 2003 01:29:16 +0100 |
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On Thu, 2003-06-26 at 00:39, Timothy Miller wrote: > Timothy Miller wrote: > > > It is my understanding that the registered memory requirement has > > nothing to do with SMP but instead with the amount of memory you have. > > The more memory chips you have, the greater the signal loading on the > > memory bus. More input drivers means more capacitance which means you > > need your output drivers to put out data sooner (relative to the clock > > edge, so registered delays by one clock) and stronger (greater drive > > strength). > > > > In an SMP system (besides NUMA), multiple processors will talk to the > > same memory through a shared memory controller (like in a Northbridge), > > so although there are multiple processors, there is still only one > > memory bus. Pulling off one CPU isn't going to change that situation. > > > Here's a URL: > > http://www.simmtester.com/PAGE/memory/memfaq.asp?cat=6&subcat=&tableView=detail&faqId=15
It does seem a bit out of date talking about PC100. But I found another source of information:
http://www.memorysuppliers.com/memoryterms.html
Registered Memory SDRAM memory that contains registers directly on the module. The registers re-drive the signals through the memory chips and allow the module to be built with more memory chips. Registered and unbuffered memory cannot be mixed. The design of the computer memory controller dictates which type of memory the computer requires.
Regarding the last sentence, the Tyan 2466 appears to be able to support unbuffered memory in slots 1 and 2 only (and the type cannot be mixed of course). The earlier 2460 doesn't allow anything but registered.
Ed-T.
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