Can my system run PC2-6400 at full 800mhz??

Question

My computer came with 1GB of PC2-5300 I want to add more memory so I went to crucial.com and they tell me this::

Q: What memory goes into my computer, and will a faster speed be backward-compatible?

A: DDR2 memory with support for DDR2 PC2-5300,DDR2 PC2-6400 speeds.

Does this mean that if I decide to take out my 1gb pc2-5300 out and install 2gb of pc2-6400 is going to run at full 800mhz or is just going to clock down to 667mhz?

Answer 1

It should automatically step up to DDR2 800 speed by reading the SPD (serial presence detect) chip that is part of the memory. So long as all RAM found is the same, higher speed, it should step up to that. That said, I have had some motherboards and/or memory that didn't get the timing quite right. In that case, I went into the BIOS and set the memory timings manually.