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Subject: Re: [OMPI devel] FDR: bad patch? (was: 1.6rc3 is out)
From: Peter Kjellström (cap_at_[hidden])
Date: 2012-05-09 10:34:43


On Wednesday 09 May 2012 10.20.47 Jeff Squyres wrote:
...
> I don't have any QDR or FDR equipment -- what's the typical active_width for
> QDR and FDR?
>
> QDR is 32000, so is that active_speed of 4 and active_width of 4? (8000 * 4
> = 32000)?
>
> FDR is 56000 (right?

Pretty much all IB is 4x to host.

4x QDR is 40 Gbps at link level => 8 Gbps data per link (8/10 coding)
4x FDR10 is 40 Gbps at link level => ~9.7 Gbps data per link (64/66 coding)
4x FDR is 56 Gbps at link level => ~13.5 Gbps data per link (64/66 coding)

/Peter

> I haven't kept up with IB specs since Cisco killed
> IB...), so what are its active_speed and active_width values?

-- 
-= Peter Kjellström
-= National Supercomputer Centre