RAM vs. RAM

M

mustardgas

New Member
Hello.

Aside from the number of GB, can someone please tell me the difference between the following: 3GB shared dual channel DDR2 (2 Dimms), and 4GB shared dual channel DDR2 SDRAM @ 667MHz?

Thanks.

-mustardgas
 
RAM usually works in dual-channels meaning it needs 2 sticks to operate at its full capacity. So 3GB is useless, because only the 2GB will be used. If you had 2x2GB, then they'd both work together for the 4GB...as from what I understand. :)

You need to have either 2 or 4 or 6 sticks etc etc for them to properly work in dual-channel mode.
 
EGS, although I learned something from your explanation (I didn't realize before what dual channel meant, or why 3GB is useless for dual channel memory), I'm still lost as to the difference between memory listed as "(2 Dimms)" and memory listed as "SDRAM @ 667MHz."
Can someone please help me with that part?

Thanks.
 
SDRAM is the current generation of RAM...DDR2 is a kind of SDRAM...just like DDR3 is.
As for the 2dimms, I think that has something to do with the way it plugs in? :confused:

www.computermemoryoutlet.com for more info about RAM and in your case you can select the make and model of your PC to find out what kind you have.
 
DIMM means dual inline memory module. DDR2 means double data rate 2. These definitions cover the dual channel nature of the memory and explain that they are used always in pairs. Your mainboard will have either 1 or 2 pairs of DIMM slots for memory. Some server boards will have more pairs than that. You always fill them in pairs with identical DIMMS. You don't leave 1 slot emply in a pair. So to get 2 GB of memory you can either fill one pair with 1 GB modules or both pairs with 512 MB modules. But you don't want to use part of a pair.

Hope that helps.
 
#5
DIMM differ from SIMM by having seperate contacts on each side.
DDR is about moving data twice per clock cycle.
Dual Channel is about the memory controller using two channels at the same time.
No parring is required for the computer to work, only for dual channel to work.
 
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3gb of ram is not useless and will work in dual channel if you have 2x 1gb sticks and 2x 512mb sticks.

alot of Xp 32 bit users go with 3gb because it can only see 3.25Gb and thats it.

but DDR2 rams that cheap these days might aswell go with 4gb.
 
DIMM is basically the RAM stick
DDR2 is Double Data Rate 2 (The second gen of DDR)
Dual Channel basically runs faster and better

You cant have 3 gigs dual channel cause you dont get 1.5Gb RAM DIMMS... or do as Nevokanaza said.

just to make things simple
 
If both types have the same number of GB, which is the better type? Or is it strictly a matter of their compatibility with the system they're installed into?
 
If both types have the same number of GB, which is the better type?
Click to expand...
The ones that are faster in terms of speed i.e. "mhz" and ram latencies. But manufacturer and ram compatability are factors also.
 
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