Depending on your CPU and its integrated memory controller, you might have one, two, three or even four "channels" that can work concurrently. The i5-4670K has two channels.

While this sounds like a huge possibility for performance imporovement, in practice the gain is on the single-percent level. It can be measured, but to actually feel the difference during use of the machine, you'll need something like a 50% speedup.

http://www.tomshardware.com/reviews/Intel-Core-i7-Nehalem,20...

So for a desktop machine, I'd say it does not matter at all. Buy what's more affordable, and maybe think about possible future upgrades.

The 1 x 8GB will run on single channel mode, when the 2 x 4GB will run on dual channel mode aka double performance (double bandwidth to be exact).

is this still true until now? I remember reading about this few years back.

Hi tuananh,

Can you give me some links that tell me more about this thing.

Thanks in advance.

You can read more about this on Intel.com (http://www.intel.com/support/motherboards/desktop/sb/CS-0119...)

I would go for 1x8GB if you want to upgrade it in the future with another 8 GB.

I am not going to upgrade atleast for a year. What would you recommend me then ?? my MB has 4 slots...