About mtune=atom

[drago01]

On Mon, Jan 24, 2011 at 6:25 PM, John Reiser <jreiser at bitwagon.com> wrote:
> On 01/24/2011 07:43 AM, drago01 wrote:
>> On Mon, Jan 24, 2011 at 3:32 PM, Sergio Belkin <sebelk at gmail.com> wrote:
>>> Hi,
>>>
>>> I've read on http://fedoraproject.org/wiki/Packaging:RPMMacros#Build_flags_macros_and_variables
>>> that mtune=atom. Just because I'm curious, why?  :)
>>
>> Why not?
>>
>> 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.

Does not contradict what I said "still being sold" ... I didn't say
they do not exist.

>> and it does not seem
>> to hurt others anyway (and most of them should use x86_64 anyway),
>
> Actually many of them should be using the new x86_32 software architecture,
> which is the 64-bit instruction set (thus 16 "general" registers, SSE, ...)
> but with integers, longs, and pointers all 32 bits.  The upper 32 bits
> of any user address are 0, and not stored in RAM (except the return address
> of CALL.)  This gives a measurable benefit on boxes with low RAM.

Ignoring netbooks/nettops boxes with "low RAM" aren't being sold either ;)