About mtune=atom

[Peter Robinson]

On Mon, Jan 24, 2011 at 5:45 PM, Richard W.M. Jones <rjones at redhat.com> wrote:
> On Mon, Jan 24, 2011 at 09:25:45AM -0800, John Reiser wrote:
>> On 01/24/2011 07:43 AM, drago01 wrote:
>> > It is the only 32bit only CPU still being sold,
>>
>> There are plenty of machines with 32-bit only CPUs (such as early Celeron,
>> Pentium socket 478, even some Core Duos [Apple Mini]) which run Fedora very well.
>> Many are less than 5 years old. In the US, that means the depreciation rules
>> of tax law strongly encourage their continued use.
>
> There's even plenty "still being sold".  How about VIA, itx, and tons
> of other small/embedded stuff that isn't Atom.

Yes, like the 2 million XO-1s using geode processors (that with the
move to i686 it was decided (no idea if it was board or FESCo) the
XO-1 was something they wanted to support in Fedora, and the other
millions of XO-1.5s that will be deployed in the coming year or two
which run on VIA processors.

> *However* optimizing for 32 bit surely has to be a waste of effort
> these days.  People who want performance should be using 64 bit
> machines.  For everyone else it's good enough that Fedora can still be
> used.  Optimizing for Atom alone is justified because Netbooks are
> used interactively.  So I think the Fedora flags are just right in
> this case.

That's fine IMO as long as it still runs reasonably on the other 32
bit platforms. Also all the nettop 1st gen atom processors are x86-64
and the 2nd gen atom netbook/nettop (N4xx/N5xx/D5xx) processors are
x86-64 now too [1]. So in most cases its just first gen netbooks plus
the devices based on z series, the later having issues anyway as they
don't have an open and supported driver for their GPU.

Peter

[1] http://en.wikipedia.org/wiki/Atom_processor#History