240-pin DDR2 DIMM limitations

[Tnias]

Thanks to BrentUnitedMem for the excellent article reviewing PC memory and the terms related to it. It was quite a helpful brush up on memory terms and their application.

However, I am curious. I need to add 2 GB to my system and I would like to make the purchase wisely. The system calls for up to four 240-pin DDR2 DIMM modules. Though I currently have 2 GB in the system, from time to time I do get errors that lock up the system usually at or shortly after boot-up; so, I figured I would be best off to buy two matched sets of modules similar to the Corsair TWIN2X2048-8500C7 because they cost no more than the standard memory the system originally called for, which was only rated at PC-5300 (667 MHz).

Accordingly, I have two questions:
My First question is regarding the Corsair TWIN2X2048-8500C7, which is designated “XMS2”; I imagine “XMS2” is a marketing term, but still, I want to make sure it is not something more that may limit the memory from working on my mobo; therefore the question is, 'Is "XMS2" a Corsair marketing term or something more than that?

Second question, am I correct in understanding that if the memory is designated as a 240-pin DDR2 DIMM module it will work in the mobo so long as the speed of the memory meets or exceeds the minimum necessary for the system; if not, what are the other factors I should consider?

 

[RetiredChief]

If the C7 denotes latency, a Cas of 7 is not to good. DDR2 800 with a Cl of 4 might be better. Ex 4 cycles @ 800 Mhz = 5 nanosec while 7 cycles at 1066 MHz = 6.57 nanosec. In this case the DDR2 800 would be faster.

As to "XMS2", it just differentiates between other models.

2nd question, if it meets,or exceeds current memory speed (Correct type ofcoarse) it should work. If it exceeds what is normally called for, it may be down Clocked.

You really should provide more info. ie MB, CPU, and is it stock or overclocked.

 

[Tnias]

For the questions I had you answered them perfectly. Thanks.
The current system is not the critical system. I am currently building an new system while I upgraded the memory in the old system. Thus, if the new memory is a bit over the top for the old system, it will not matter because that computer will be put back like it was when I began the build of the new system and it will go to my children after I have all of the components that will be going into the new system. I'm putting a few dollars at a time into the build so it may take a couple of months to complete the build. Meanwhile, I hope to enhance my current work in progress with the new memory.