"John T" wrote in message
...
Generally, if the PC recognizes the RAM, it should be able to use it. Be
aware, though, not all memory is compatible. If you have memory using
different clock cycles, for example, you may experience instability. Also,
if you get memory that is too slow or too fast for your system,
instability may result.

I've never heard of memory that was rated *faster* causing incompatibility
problems. I guess I can't rule it out, but it would certainly surprise me.
I would guess that even when it *appears* that it's a case of the memory
being too fast, it may turn out to be actually related to access timings for
the memory being incompatible instead.

Of course, you're right that "too slow" is definitely an issue...all sorts
of bad things can happen if the RAM is rated slower than what the
motherboard is using it at (noting, of course, that on some motherboards the
memory controller can be underclocked to compensate for too-slow memory).

Also, on most motherboards, matching memory sticks (DIMMs, SIMMS, whatever
your computer is using) is mainly important when the sticks are on paired
channels. For dual-channel memory controllers, these are the pairs of
channels that run the sticks in parallel, and for other controllers, there
are still usually just pairs of slots that are dependent on each other. The
motherboard manual (or PC documentation, if it's a prebuilt system) will
generally describe the matching requirements. You can often get away with
unmatched memory, as long as the unmatched memory isn't paired up in
mutually-dependent memory slots.

Pete