Memory compatibility

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It is easy to find out which memory is recommended for a given machine.
What is not easy it to determine, for instance, to what extent two
different types of memory can be used on that machine.

Case in point:
Manufacturer recommended: 200 pin PC2700, DDR 333, SODIMM
Available memory :PC2-5300S-555 DDR2667Mhz

More generally, is there a site which helps determine interoperability
and explaining what to watch for. The subject being complex, I strongly
doubt I would ever gain enough knowledge to be able to make reliable

I believe installing the wrong type of memory is one of the surest way
to kill a laptop, and that trial and error - even if there is a form
factor compatibility - is an absolute NO NO. What do you think?

Best wishes to all for this coming New Year.
John Doue

Re: Memory compatibility

Well, it's not that hard.

First rule:  You ALWAYS have to use the right KIND of memory.  For our
purposes, Pentium 4 and later computers have used the following KINDS of

RDRAM (never used in any laptops)

General rule:  Any given computer takes one and only one of the above
types of memory and you can't use any of the other types, period (there
are some exceptions to this rule on a relatively small number of desktop
motherboards, I am not aware of ANY exceptions in laptops).

In your case, "PC2" ("Available memory") is DDR2, and PC2700 is DDR,
these are different KINDS of memory, ***NO***, you cannot substitute OR
mix them.

Second rule:  SOME laptops have a capacity limit.  Example:  The Toshiba
1400 series laptops and the 2400 series laptops are ALMOST identical.
They are so identical that they are both covered by a single Toshiba
service manual and they use the SAME BIOS files and drivers (ALL
drivers).  But in the 1400, the maximum size memory module that you can
put into the two available DDR memory sockets is 256MB (512MB total)
while in the 2400 you can install two 512MB modules (1GB total) (if you
put a a 512MB module into a 1400, it won't even POST).  [Reason:  a VERY
slightly different version of the Intel 845 chipset (suffix is
different) is used in the two machines.]

If you use incompatible memory of the same TYPE (see above), you
generally won't do any harm, but it generally won't work right (or, at all).

John Doue wrote:
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** Posted from **

Re: Memory compatibility

Barry Watzman wrote:
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Thanks, Barry, at least, I have now a basis and can avoid the most
glaring errors!

Happy new year.

John Doue

Re: Memory compatibility

John Doue wrote:
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Re: Memory compatibility

spamme9 wrote:
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Thanks for those useful links

John Doue

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