I am thinking about upgrading the complete FAS2750 stack we have from IOM6 to IOM12. Does anybody have any experience with the performance increase when doing this? The SAS and SSD disks we have do all support 12 Gb/s, only not the SATA shelf. I am wondering or it's worth the money to upgrade all IOM6 to IOM12 modules. In theory there should be a 100% perofrmance increase isn't it?
I've only seen 6Gb/s be a bottleneck on high end AFFs. You have to be pumping over 1 GB/s through them disks to even begin to hit limits. Don't forget you have 4 PHYs, so you get 24Gb of througput functionally, or about 3 GB/s per stack.
Module Operational Shelf Name Shelf ID Serial Number Model Type Status ----------------- -------- --------------- ----------- ------ ----------- 1.0 0 XXXXXXXXXXXXXXX DS224-12 IOM12E Normal 1.1 1 XXXXXXXXXXXXXXX DS2246 IOM6 Normal 1.2 2 XXXXXXXXXXXXXXX DS2246 IOM6 Normal 1.3 3 XXXXXXXXXXXXXXX DS4246 IOM6 Normal 1.4 4 XXXXXXXXXXXXXXX DS224-12 IOM12 Normal 4.0 0 XXXXXXXXXXXXXXX DS224-12 IOM12E Normal 4.1 1 XXXXXXXXXXXXXXX DS2246 IOM6 Normal 4.2 2 XXXXXXXXXXXXXXX DS2246 IOM6 Normal 4.3 3 XXXXXXXXXXXXXXX DS4246 IOM6 Normal 4.4 4 SHFGD1703000417 DS224-12 IOM12 Normal 10 entries were displayed.
Our SAS disks can run on 12 Gb/s, our SATA have a 6 Gb/s limit.
It's the plan to replace all IOM6 for IOM12 if that brings a performance boost.
from the 12GbSAS deck - A maximum of one transition from 12Gbps to 6Gbps modules is supported
It is a bit unclear whether embedded IOM (IOM12E) is counted here (it says "external stack" about entry systems). Also it seems the primary use case for lifting this restriction is extending existing IOM6 stacks by IOM12 shelves. So I am not sure if even IOM12E - IOM12 - IOM6 - IOM6 would be valid ("IOM6 CIRCLE ports must be used for connection to IOM12 ports" and when going from IOM12 to IOM6 we connect IOM6 with SQUARE port ...).
So it amounts to - is IOM12E - IOM6 speed transition or simply (IOM6) stack attachment?