R510 memory issue

I just aquired a Dell R510 with dual X5670

I also got 8 stick of RAM
(4x) DDR3 RDIMM 4GB 1RX4 PN: M393B5270CH0-YH9
(4X) DDR3 RDIMM 4GB 2RX4 PN: M393B5170FH0-YH9

As far as i know they have the same spec expect the number of memory rank
The R510 seem to have a weird memory config with 2 banks separated in 3 channels.

BANK1 (slot 1 2 3) BANK2 (slot 4)
Channel 0 (slot1) (slot4)
channel 1 (slot2)
channel 2 (slot3)

Im planning to run this in Optimizer mode.
Any idea how i can populate all the slot with my current memory without getting
a geometry of a unsupported dimm error?

Or i just need to get 4 more stick of one or the other mem config?

thanks in advance!