Mac Pro RAM Configuration help

[-BigMac-]

Hi guys,
I bought myself 2x4Gb Corsair RAM modules.
My MP 2.8 Quad had 3Gb by stock. How do i organise the RAM modules inside the MP for maximum performance? Does placement matter?

I heard its important to have the RAM in multiples of 3. Does that mean i would be better off with 9gb (4, 4, 1) config. rather than a 10gb (4, 4, 1, 1)?

P.s I realise i will have to get rid of 1 of the modules

Thank you

 

[dknightd]

You only get benefit from 3 channel memory if all chips are the same, and apparently even then it is minor advantage. so I'd use 4-4-1-1 based on what you have.