CrayLink cabling prohibited on Origin 2000 deskside

[Scott Quinn]

On Dec 24, 2007, at 1:39 AM, Richard wrote:

> Origin2000 and Onyx2 Deskside and Rackmount Installation Instructions
> Document Number 108-0155-002
> 12/96
> pg. 6-36
>
> 	"Caution: You cannot install CrayLink interconnect cabling on a
> 	standalone deskside system because of power grounding
> 	requirements.  The power differential between two interconnected
> 	modules should not exceed 500 millivolts; otherwise severe damage
> 	can result to boards and other components inside the chassis.  The
> 	power distribution unit (PDU) inside the rack provides a common
> 	ground source for the modules.  In addition, the groundstraps are
> 	installed on multirack configurations to help provide common
> 	grounding across the racks as described in Section 6.16"
>
> That seems about as blunt as you can get.

I'm not sure about that- you can CrayLink to Origin 200s  together, the 
only requirement being the common ground (plug them into sockets with 
the same ground, run a thick ground between the chassis, or (as I have) 
stack them one on another if they don't have the skins).

If you can do it with an Origin 200, then you can do it with a Origin 
2000, since the hardware is very similar. You might need to get 
creative with the grounding, though, and make sure it's done well 
(perhaps two grounding straps of ~12AWG connected to different 
locations). Perhaps SGI did not design the ground point into the O2k 
deskside as they did in the O200, but we're a creative bunch here.