stupid as I am I bought ocz platnium pc3 10666 a month agao. Today I
bought a Asus M4A89GTD PRO, AMD 890GX MB. I also learned that most MBs
are dual channe. Now I know it doesn't make sense to install the three
moduals. My question is: Can I buy another brand pc3 10666 2gb ram,
since ocz doesn't sell 2gb moduls induvidually, or can I install a 1GB
ocz modual so i will have a total of 7GB? Does that make sense or will
I have a loss of the dual channel tech. advantage?
If you install all three, the first channel will operate in dual channel mode, this should be verified in the BIOS. Hoever the third module will only operate in single channel mode. I cant see this really being a problem. You cant install mismatched pairs of ram in a dual channel architecture so your adding a 1GB module in with the 2GB module wont work. If you buy another 2GB module from some other manufacturer, just make sure it is the same specs as the ones you have already. this is no guarantee it will be compatible, but chances are good that it will work.
Rules to Enable Dual Channel Mode
To achieve Dual Channel mode, the following conditions must be met:
Matched DIMM configuration in each channel
Same Density (128MB, 256MB, 512MB, etc.)
Matched in both Channel A and Channel B memory channels
Populate symmetrical memory slots (Slot 0 or Slot 1)
Configurations that do not match the above conditions will revert to Single Channel mode.
The following conditions do not need to be met:
Same timing specifications
Same DDR speed
Memory channel speed is determined by the slowest DIMM module populated in the system.
*This really depends on your motherboard. Some manufacturers use a color
-coded system (meaning use the same colors) and some require that you use the symmetrical approach (meaning same slot on both channels).
Now that that's out of the way... If you do a 3x2GB + 1x1GB, you won't achieve Dual Channel, as the density is unmatched across all modules. So here are your options: