Dual channel question for DDR2

[Ultra Wide]

I have an intel/Dell mobo with i955X chipset which supports dual interleaved mode.

I currently have 2 x 512MB PC4200 in dual channel mode.

I ordered 2 x 1024MB PC5300 DDR2 kit.

So, if I run all 4 sticks together do I get 2 x dual channel mode? or is it just 1 x dual channel?

DIMM 1 + DIMM2 = Channel A
DIMM 3 + DIMM4 = Channel B

OR

DIMM1 = Channel A
DIMM2 = Channel B
DIMM3 = Channel C
DIMM4 = Channel D

I am guessing that just having 2 x 1GB @ PC5300 will be the best performance???

 

[(cf)Eclipse]

most you'll get is dual channel.. just two sticks in each channel. that's assuming that the sticks play nice with each other