QUOTE(ykgen @ Jun 27 2012, 02:48 PM)
just added a 4gb 1600mhz ram to my G55
how come the ram is running at single channel instead of dual channel? is this normal?

ykgen, in order to run in dual channel, you need to slot in 2 rams at the same channel slots.
Meaning, the maintenance rams slot is channel 1. The non accessible ram slot is channel 2.
So what you are doing now is having 2 ram on 2 different channel. So that is why you are not in dual channel. The only way to rectify this is:-
i) Buy another ram with the same size and speed and put into your maintenance ram slot. (12GB RAM total)
ii) Open up the non accessible ram slot and put in your new ram to make it dual channel (8GB RAM total)
iii) Same as ii but pull it out and put into your maintenance ram slot to make it dual channel (8GB RAM total)
Hope this helps.
PS: RAM must be same size and speed, else dual channel won't activate. Brands usually wont be an issue but recommended same brand. That is why Dual Channel RAM they sell in pairs. Still wont be a big issue.
This post has been edited by Joker: Jun 27 2012, 03:19 PM