getting new ram, want 2b comp. with old.

[hjohnson]

Ok, my old ram: 2 sticks, both say VS512MB400C3

I thought I had gotten Dual Channel ram, but reading this number I'm not sure ( I'm probably remembering wrong, since it was over a year ago I bought it). Wouldn't a dual channel set have KIT in the number?

 

I need some new ram, cause the old might be dead, but if it's not dead, I want them to work together. My board manual (asus p4p800-e deluxe) says if you insert a single-channel stick with dual channel sticks, they will all run as single channel. If my old memory is already single channel, a single stick of single channel will be perfect, but if it's dual channel, I'll be sort of downgrading if I get one stick. On the other hand, If they're not dual channel, then there's no sense filling up my slots with more sticks than I need.

 

Also, I hear that the Cas-Latency needs to match. Is that "C3" at the end of the number indicating a cas latency of 3?

 

Unless I find that my old ram is dual channel somehow, I'm just going to get another stick with the same model number.

 

Is there anything else I should consider? Voltage maybe? I'm kinda new at this memory stuff, and I just want to make sure I get the maximum performance out of it.

 

Thanks!

 

-heidi

[RAM GUY]

Dual channel is a function of the memory controller, you would only need to use two modules that are the same exact part# and install them in the correct slots to enable dual channel. If you have two VS512MB400 modules they should run in a dual channel MB with out problems or Two VS512MB400C3 modules but you cannot mix these two different part numbers. Just try them and if you have a problem let us know. But I think you will be fine, just load setup defaults and set the memory voltage to 2.7 Volts and you should be good to go.

[hjohnson]

I see. I didn't realise the "dual channel" was all in the mobo.

 

So with 2 sticks of vs512mb400c3, they were running dual channel. If I insert a 3rd stick, how much will the performance of the other two sticks be hampered? (if at all) Thanks again. I'm learning so much from this forum!! :)

 

-heidi

 

oh. is the c3 at the end an indication of cas latency, or something else?

[RAM GUY]

Depends on the MB, but I would not suggest 3 modules with the MB you have listed. 1,2 or 4 modules but two would give best performance.

[hjohnson]

hmm...that puts a damper on things.

would it be better to have two 512mb sticks and two 256mb sticks?

[ZeroZero]

Depends on the MB, but I would not suggest 3 modules with the MB you have listed. 1,2 or 4 modules but two would give best performance.

 

What Wired are saying are that with 1 memory module = single channel, with eithter 2 or 4 modules in memory slot you can run them in dual channel or as in single channel mode.

 

It is easier to understand this limit of memory controller if you know that each module are 64 bit (=single) and in 128 bit (=dual) they run in pair. That is also why you should have memory there are "twin" in every sense as they process the same date at the same.

 

In most cases you will get a decrease in performance with three modules that can hamper your attemt to get a more responsive computer.

 

In BIOS (look up you manual for your motherboard -very often you can also find it online as PDF-files) you can set up how the memory will work, but you have to understand what setting to change. Some setting could destroy your memory modules if it is to high like Voltage in memory.

 

Memory Basics from Corsair. This (link - point here) is a presentation of how memory works and explain features as Cas latency (CL) and such things. You will need flash player to watch this.

[Wired]

What Wired are saying are that with 1 memory module = single channel, with eithter 2 or 4 modules in memory slot you can run them in dual channel or as in single channel mode.

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