question regarding mixing memory brands

[Sunny129]

ok guys...its been a while since i cracked open a computer and worked with the hardware, and i've forgotten all the rules about mixing and matching memory. here is my situation: i have a 256MB stick of ACER PC3200 (400MHz) DDR CL3 with Hynix chips, and i need to add another 256 MB of memory. what are my limitations? (it should help to know that this computer will be used for checking email and surfing the web - no games or intense applications will run on this system. thus i will not be overclocking the system or try to get the most out of the memory through the BIOS settings...i just want the additional stick of memory to be "plug-n-play"). does the brand of memory have to be the same, or can i buy something other than ACER, so long as its the same speed memory? which brings me to my next question - is memory speed itself a limitation (i.e. must the new memory be PC3200 (400MHz) like the original)? sorry for all the dumb questions, but i did search "mixing memory" and came up with squat.

TIA,
Eric


*EDIT* - another question: this platform is capable of running dual channel memory, even though it only came with one 256MB stick of RAM. in order to take advantage of "dual channel" capabilities, must the two sticks be the same capacity (i.e. both 256MB of space)?

 

[king4lex]

does the brand of memory have to be the same, or can i buy something other than ACER

The brand does not have to be the same, but some motherboards have trouble with certain brands. Just make sure you don't buy some cheap off-brand memory. RAM isn't like generic presciption drugs: cheaper memory is often unstable or slow.

so long as its the same speed memory [...] is memory speed itself a limitation

If you buy different speeds, just put the slower memory in the first slot and they should both run at the slow speed.

in order to take advantage of "dual channel" capabilities, must the two sticks be the same capacity

Nope, you can use different capacity sticks.

Hope this helps!

--king4lex

 

[Lemon law]

To Sunny129,

There is a bit more to understand than that. First question to ask---is it ecc ram or non-ecc. In short, most memory web sites will let you take your motherboard model and they will tell you what is compatible and what is not---then you want something as fast or faster than what you have---so the stick you have is the limitation rather than buying a slower stick and having your existing ram downclock itself to match the slower ram you purchased.

And as a been there done that---you will experience dramatically faster boot times by going from 256 MB to 512 MB.----I think I overpaid at a local store---but the 256 MB stick I bought was only $35.00
new and came with a lifetime guarantee.---and exactly matched the speed of the existing other brand ram I had in the computer---but I knew that going in because I checked the motherboard model on the memory makers website.

And you can check the clocking of your existing ram by downloading and installing the free cpuz or the everest 2.2 versions.

 

[Sunny129]

thanks for the quick responses guys. i believe this is more than enough info to make my purchasing decision.

 

[computer]

In order to use memory as dual channel, the sticks DO have to be identical. You're running, so to speak, parallel memory and if they are not identical, even if a PC will boot they are running far below optimal performance; and because it's sort of parallel, can lead to instability. If this would not be the case, no one would sell DC memory kits. Even with the matched DC memory kits, they won't always work because one of the sticks may be sub-par to the other. I see this all the time. I've never seen a DC memory kit that I didn't have to RMA to get sticks that were REALLY matched as they should be.

If NOT being run in dual-channel, then all you have to watch out for with that (other than ECC or non-ECC, and CAS) is lying jerk memory vendors. The cheapest prices are usually for high density modules (that most mobo's won't run), or other "fine print" like "will not work in Intel platforms" or "will not work in VIA platforms", etc. etc. Just be sure to know ALL ABOUT the memory you may buy.

You can mix for example CAS3 and CAS2.5 in single channel mode, but it's not a good idea.

 

[computer]

And to answer your question directly about Acer: that memory isn't really "Acer", it Hynix. Acer, like most other memory "labelers" don't make memory. They OEM it from Samsung, Infineon, Micron, or, Hynix, and others. It's possible to probably find an identical stick, but it could be packaged by Kingston for example, or several others.

You can even get two of the exact same model # of a memory module, like packaged by Kingston, and one have totally different chips! The published specs are usually minimum, so if in this example Kingston says it's PC3200 CAS3, they will both do that, but the one with a "better" chips may actually do CAS2.5 and or PC4000.

 

[king4lex]

Originally posted by: computer
In order to use memory as dual channel, the sticks DO have to be identical.

Quoth Wikipedia, " It is not required that identical modules are used, but it is often recommended. One module of 512MB RAM could be installed in bank one and a 1GB module could be installed in bank two. Modules rated at different speeds can be run in dual channel, although the motherboard will then run all memory modules at the speed of the slowest module. "

See: http://en.wikipedia.org/wiki/Dual_channel

Wikipedia says it is possible. You say it cannot be done. Who's right?