Advice on ddr3 ram

How is that 5Gb split? 2x2Gb + 1Gb?
depending on your Mobo's memory channels you may be better dropping to 4Gb or up to 6Gb, the mixing is going to be messing you up a bit as it is
Moto

No, 5 single chips and sometime i think about buying another one

Wow single chip...mm I don't hear 5gb ram ,never.
Check again your ram maybe 4gb or 6gb?

No you dont understand i mean 5x1gb ram. 5chips an other slot is available

So what do you recommend me to do ?

Ok, sigle ram 1333 it,s mean your ram run at 667, but for good oc use dual ram, use 1 ram for oc not worth.
I think if you enjoy with 1 ram just run at default.
If you want oc get 1 ram same clock 1333. That better for you. In above moto show guide overclock.

I have 5 gigs of ram ddr3 but i dont have a single chip but 5 so my mobo has 6 ram slots and i have filled the five

with 6 slots I'm glambling your on a triple channel Motherboard,
so either add more more stick of 1Gb or remove 2 sticks to get the triplechannel benefit, you should have different coloured slots, fill either colour unless your mobo manual says a specific set should be used
Moto