can I pair same brands but different gb?

[Katy_1]

My latest ram is kingston 2gb ddr3 pc1333 and i am planning on buying a kingston 4gb ddr3 pc1333 so is it available to pair them making them a 6gb ram or not?

 

[thx1138v2]

It will probably work but not well. The critical thing is the CAS latency shown as "CL". It most likely won't work if they are not the same unless you manually configure both sticks to the same CAS which would be the slower of the two. If your motherboard's BIOS doesn't support manual RAM configuration it's a toss up whether or not it will work at all.

Even if you get it working you will lose the dual channel capability. The RAM will only work as interleaved memory which means it doesn't read/write the two channels at once but treats them more or less like one 6Gb stick. So you lose the Double Data Rate (DDR) capability.