[GTALUG] War Story: Asus UX305ca SSD failures

[D. Hugh Redelmeier]

We bought two Asus ux305ca notebooks about three years ago.  The Microsoft 
Store had a remarkably good deal on them.  I'm not the only GTALUGger to 
buy this notebook.

Two years ago one of the m.2 SATA SSDs suddenly stopped working.  If I 
remember correctly, it didn't even show up as a disk.

Last week the same thing happened on the second notebook.

The only warning was that a few days earlier the firmware forgot what
to boot.  I easily fixed that by telling it again.  This could easily
have been a CMOS battery problem but I guess it wasn't.

The computer acted as if the drive were not there.  I installed it in a
different machine and it was not detected in the other machine either.
The firmware ("BIOS" is not the correct term) on both machines failed
to see it.  A live Fedora system (booted off a USB stick) failed to
see it.  It's dead, Jim.

Lesson: SSDs don't give you warning about failures.  Much worse (in my
modest experience) than HDDs.  Backup now.  I'm skeptical about
S.M.A.R.T. for SSDs.

Inference: there may have been something wrong with the model of SSD
used by Asus in the ux305ca.  Two out of two failed us.  Micron M600
256GB.  I've had other SSDs fail, but only in the early days of SSDs.

It's fairly easy to replace such a drive.  You need to remove about a
dozen screws and pry open the case.  For the ux305ca you need a TORX
T5 driver.  For prying: use an old credit card, guitar pick, or
spudger (don't use a screw driver since it may scratch or scar the
case).

Lesson: search YouTube for videos on taking apart you notebook.  They
are not perfect but they give you an idea of what you are in for.

I'm actually doing musical chairs with SSDs.  I have a spare NVMe SSD
but the Asus can only take an m.2 SATA drive.  I have a Dell notebook
with an m.2 SATA drive but it can also support an NVMe drive.

- broken m.2 SATA drive from Asus => ???
- m.2 SATA SSD from DELL notebook => Asus
- new unused NVMe SSD => DELL notebook

Background on SSD interfaces:

First there were mSATA SSDs.  Those were supported on some older
machines (eg. ThinkPad T20 and T30 notebooks).

Then came NGFF ("New Generation Form Factor") connectors and
interfaces about the time of Haswell processors from Intel.  They were
quickly renamed to m.2 (because it rolls of the tongue, doesn't it?).

Originally m.2 drives used the same SATA interface.  Recently, the
NVMe interface was added.  It's just like PCIe on a different
connector.  That interface is much faster than SATA.  It's so good
that most new desktop motherboards support it -- it's not just for
notebooks.

I'm not sure when one would notice the speed difference between SATA
and NVMe.  SATA SSDs are already almost always a lot faster than HDDs.
The first generation of NVMe SSDs had internal bottlenecks that may
have limited the improvement over SATA.