R710 add memory but can't work

Dear all:

My PowerEdge R710 original have 

A2 A3 Samsung M391B5673EH1-CF8*2

A5 A6 Kingston KVR1333D3N9/8G*2

It can work well well.

But I buy Kingston KVR16R11D4/16*2 and add on my PowerEdge R710 A8 A9, but it can't work.

I try only A1 A2 KVR16R11D4/16*2, it can work.

A1 A2 Samsung M391B5673EH1-CF8*2

A4 A5 KVR1333D3N9/8G*2

It can work.

A1 A2 Samsung M391B5673EH1-CF8*2

A4 A5 KVR16R11D4/16*2

It can't work.

Finally I find KVR16R11D4/16*2 only can work alone, put other memory on won't work.

I updrade bios to 6.4.0, but useless, KVR16R11D4/16*2 only can work alone.

Have anyone can help me to solve this problem?

Thank you very much!!!