[sf-lug] Don't buy a computer with Windows Signature edition installed!

[Rick Moen]

I wrote:

> Some Lenovo 'Signature PC' laptops have a chipset for the hardware
> interface to the SSD that is BIOS-locked into a so-far-obscure fakeraid
> mode, rather than leaving AHCI mode enabled or selectable.  The only
> part of the wild tale that's (according to accounts I consider reliable)
> true is that the 'Signature PC' program requires that covered machines
> must be be locked into their highest performing mode in the BIOS -- and
> this happens to be be the NVMe fakeraid mode in this case.
> 
> Which is currently problematic because nobody's yet figured out a Linux
> dmraid driver for the weird-ass fakeraid operating mode.
> https://www.reddit.com/r/linux/comments/53ri0m/warning_microsoft_signature_pc_program_now/

Semi-correction and further comment:

It's misleading, it turns out that this laptop is locked into what is
labelled a 'RAID mode'.  More about this from comments on Matthew
Garret's blog:


  Date: 2016-09-22 07:15 am (UTC)
  From: teaparty.net

  If I understand mjg59's argument correctly, the issue is not RAID. As you
  point out, that's not a laptop thing.

  The issue is that Intel have not told anybody how to properly-manage
  power in their hardware; instead, they have released a binary-blob
  driver for Windows that just does it right. However, for the driver to
  do things right, Microsoft's driver mustn't bind to the hardware first.
  The easiest way for Lenovo to achieve this is to put the hardware into
  RAID mode, and not to let it come out. That means the MS driver examines
  the hardware, decides it can't deal with it, and ignores it, leaving the
  Intel driver to come along and claim it.

  Presumably the Intel driver is perfectly happy to run in single-disc
  JBOD mode, but it _does it with the right power management_. The end
  result, according to Matthew, is "correct power management
  configuration, battery life is better and the machine doesn't melt".

  I'm not saying it's a good thing, and I don't think Matthew is either.
  It's just the easiest way for Lenovo to deal with Intel's stupid
  secret-sauce power management, in a Windows context.

Or, more bluntly:

  Date: 2016-09-22 02:52 pm (UTC)
  From: (Anonymous) 

  Stop getting hung up on the word 'RAID'. This has nothing to do with
  actual redundant arrays of inexpensive disks at all. The mode is called
  'RAID mode' but it might as well be called 'make power management work
  better mode', because that's the actual reason why Lenovo wants the
  controller set to that mode: power management works better when the
  drive controller is set to that mode.

Anyway, do _not_ get a bleeding-edge laptop and then expect not to have
Linux troubles on it.  Maybe Daniel can elaborate about how he recently
spent until 2 am after a CABAL meeting getting a Linux installation to
work properly on a spanking-new ASUS laptop with the now-infamouse Intel
Skylake architecture.