DcDewick, Only having 2 8GB won't work for you. To be able to use them you would need 4. The R710 has 3 channels per processor, with it being in ECC mode channel 0 on A and B is disabled.  So you would have to go 8gb in A2, and 3 and B2 and 3. Then the 2gb dimms in A5, 6, 8, and 9 and B5, 6, 8, and 9. 
I've an R710 with 16Gb installed in Advanced ECC mode: 8 x 2Gb modules (Samsung M391B5733CHD-CH9, 2GB PC3 10600E 1333MHZ DDR3 ECC) in slots A and B, 2,3 and 5,6. I've got spare 2 x Integral NT8GC72B4NB1NJ-CG, 8GB DDR3 1333MHZ ECC REG CL9. Can I use these two memory modules to up my memory to 32Gb? If so, how?
R710 Memory upgrade