Z400 RAM config . .

Hello HP experts,

Please advise on how should I position 2x Stick of 4GB total of 8gb in my Z400 workstation (6 dimms)

base on the link below that  Z400 is a three-channel design and I should first filling the black slots and then filling the white slots.

Memory configuration and optimization

http://h20331.www2.hp.com/Hpsub/downloads/HP-Z400-Workstation-memory-configuration-and-optimization.pdf

But I don't see an example for a 2 sticks of 4GB...

Thanks in advance.