21 IMac RAM configuration

[Jurph]

Hi!

I have a late 2009 21.5'' IMac that cam withe the standard 4Gb RAM (2x2GB Modules)

Now I bought two additional 4Gb RAM modules, so I have 12GB in total.

What ist the correct disposition of the modules in their sockets that allows to preserve dual channel capability?

Right now I have inserted them like this:

BANK 0/DIMM0 4 GB
BANK 1/DIMM0 2 GB
BANK 0/DIMM1 4 GB
BANK 1/DIMM1 2 GB

is this correct?



Also, is there a way to check if my mac is really running in dual channel?

Thank you for your responses

 

[Veryold]

You are correct. The slots are in horizontal pairs and you will have the 2x2 in the top slots and the2x4 in the bottom slots.
I do not believe there is any way of knowing if the memory is running in dual channel. In your set up it should be . The difference is not all that great and has been estimated at 5%. With the extra ram you should have noticed a big increase in performance.