Quoted from kpg:Here's a better pic- the motherboard in TH is a dual channel memory board- so when using memory modules, make sure to install them in separate channels so they can operate in Dual Channel mode
Example, with two sticks- make sure they are both installed in the same channel - the slots should be color coordinated like shown in this pic. Do not put one stick in a channel 1 slot, and another in channel 2. Both should be in the same channel to operate as a pair.
Actually, it differs from mainboard to mainboard. The color coding is not standardized. Sometimes different colors indicate different channels, sometimes different colors indicate the same channel. It sucks but that's how it is.
You definitely want your DIMMs in different channels to take advantage of the dual channel architecture. (In your post you first say to put them in different channels, then you say to put them into the same channel?!)
I don't know if the POST screen is visible when TH is booting, but it usually tells you whether your RAM is running in dual channel mode. Might be hard to read without a pause key though.