IBM position on Mini SAS Connector

[Theodore Vojnovich]

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Here is IBM's view and position on the Mini SAS proposals:
IBM's position on the high density SAS connector definition prefers the 
Molex solution subject to providing some additional information:
   - Current reasons for the preference:
	     - Wiring, PCB, and placement constraints appear to be more 
feasible with the Molex solution.  Specifically
		     - Other proposals indicate that the wiring channels 
needs to cross over each other to get to the connector
		     - This drives more layers in the board and 
constraints on the physical channels
	     - The connector arrangement in 1 dimensional scale out 
provides the following:
		     - Smaller footprint on the board
		     - Takes advantage of the perpendicular axis to the 
board for connector pins and such.
		     - Less connector complexity (aka cost) since no 
interposer
		     - No "over/under" issues on extracting a subset of 
ports  (ie easy user access to the port group...aka stays away from the 
issues with stacked RJ45s)
	     - Although common to all proposals, it should be required 
that this connector be supported for 6G and 12G operations
		     - Having it for 6G would allow platforms over the 
next couple of years to have a connector/cable scheme that last beyond 6G.
   - The additional information that needs to be provided/resolved:
	     - The connectors should be keyed to prevent wrong or flipped 
insertion
	     - The connectors should be shielded on all sides to prevent 
physical damage and EMI issues
	     - The number of plug cycles intended for this family of 
connectos needs to be stated and should probably be on par with the plug 
cycles of the current connector schemes.
	     - There needs to be an addition to the proposal to allow 
hybrid cables so that equipment with older connectors can be attached to 
equipement with this new connector.
Thanks
Ted Vojnovich
STSM Blade Center Storage Solutions
IBM Corp.
N202 / B205
3039 Cornwallis Dr
RTP NC, 27709
Voice:	919-254-0730 (T/L 444-0730)
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Cell Phone:   919-656-5061
Email:	tbvojnov at us.ibm.com