Memory replacement

James Cameron quozl at
Wed Mar 9 16:37:46 EST 2011

On Wed, Mar 09, 2011 at 11:31:24AM -0500, Kevin Gordon wrote:
> OK, the little 8GiB microSD card inserted into an SD adapter, inserted
> into the external SD slot, passed the dir test that James said to
> perform at OFW.  Didnt complain.

Good.  You must test again if you change cards, by the way.

> However, it is a "Class 2" Sandisk card, so it might not really be the
> right way to go.

You can fs-update it in the external slot, and this will give you a good
indication of write performance in two ways; the flickering of the
storage LED during the fs-update, and the total time shown at the end of
the fs-update.

ok devalias fsdisk /sd/disk at 1:0
ok fs-update ...

Then you can boot it, and the laptop should boot from the external card
and not use the internal card.

> Before I do the surgery, armed with silver heat sink paste,

I've never tried heat sink paste, I don't know if it is recommended, but
there's a thermal test in OpenFirmware you might try before and after.

ok test /switches

It instructs you to close the laptop, after which you should open it,
then it asks for e-book configuration.

Note the temperature rise.  Note your environment temperature so that
you can reproduce the test reliably.

> advice please: go, no-go, spend the extra pennies and get a Class
> 4/6/8/10.

A faster card is certainly worth getting, but "Class 4/6/8/10" doesn't
really indicate how fast it will be.  The definition of these classes
corresponds to sequential write rate by a camera to a FAT filesystem,
not random writes to an ext3 filesystem!

> All I know for sure is the 2GiB card in there has to be replaced.
> There are progressively more and red squares appearing on every
> refresh,

I don't agree with your assessment.  It might easily be another defect,
and not the card itself.  If it were in my hands I would do more write
testing on the internal card, using Tiny Core booted from USB.

You might defer the surgery and instead use the external slot for a

James Cameron

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