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Re: Does mfi write-back cache work for anyone?

On Thu, Jan 10, 2013 at 01:31:45PM +0100, Manuel Bouyer wrote:
> I suspect the key point is isSOHGood: you have it set to "no", I have it
> set to "yes". I didn't find in documentations what this means exactly,
> but I suspect this is the firmware's idea of the BBU status or use.

It turns out this is set according to a ratio of the battery's actual vs.
nominal (about 1800mAh on the PERC 5i) capacity.  If it falls below some
threshold, SOH becomes "bad" and the adapter firmware disables write
back cache but the adapter BIOS *does not* print the "missing or bad
battery, disabling cache" warning as it does with a completely dead

I got a shipment of "new" batteries some of which had capacities as low
as 300mAh.  Though others are fine (1700-1800mAh) I guess I'll be
returning the whole bunch.  I'm told by a coworker that the "6i"
batteries work fine on the 5i controller (this is not true for the
5e however) and that since the 6i is a newer controller, the batteries
tend to be fresher as well.


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