[OmniOS-discuss] expected memory bandwidth of Supermicro X9DRi-F and X9SRI-F

[Paul B. Henson]

I have two servers I'm putting together, one using the X9SRI-F and the 
other the X9DRi-F motherboard. Both have Intel Xeon E5-2620 processors 
(one for the X9SRI-F and two for the X9DRi-F). Both have Crucial 
CT2KIT102472BB160B (2 x 8G 1Gx72 DDR3 PC3-12800 Reg/ECC) DIMMs installed
(6 on X9SRI-F for 48G, 8 on X9DRi-F for 64G). Testing the memory, the 
X9SRI-F shows bandwidth of about 12GB/s, whereas the X9DRi-F shows only 
about 8GB/s. This seems considerably lower than the 42GB/s bandwidth the
E5-2620 is supposed to support, even considering this isn't the most 
expensive/fasted RAM on the market. I'll also suprised at the 4GB/s 
difference between the single-proc and dual-proc board.

I was wondering if anybody else was using these boards and if so what 
memory bandwidth memtest86+ reports, as I've been unable to find a good 
source of expected bandwidth (versus theoretical maximum bandwidth). I 
asked supermicro if it was expected to have such a difference in 
performance between the single processor versus dual processor board, 
and all they would tell me is "we don't support that memory" <sigh>.

Thanks…