[arch-dev-public] Processor Generation++

[Paul Mattal]

Simo Leone wrote:
> On Mon, Mar 17, 2008 at 02:26:42AM -0500, Simo Leone wrote:
>> Let's start off by saying that this is just me floating an idea out there,
>> it's not so serious (yet...).
>>
>> I've been toying around with the idea of starting to build our
>> packages with --march=pentium2 instead of i686. This would mean that our
>> binaries would make use of the MMX instruction set, and that our
>> packages would no longer run on PentiumPro or older processors.
>>
>> My logic here is that we are comitted to being a bleeding edge distro,
>> so I think it very much fits our philosophy to phase out older
>> processor families when they are hardly used anymore. Intel hasn't
>> manufactured PentiumPro's since roughly 1998. The number of users
>> running Arch on 10-year-old boxes must be something very close to zero,
>> so I don't think we'd be disappointing anyone. Also making use of the
>> MMX instruction set would give our multimedia apps a boost, and might
>> make some other software inperceptibly snappier (gogo placebo effect!).
>>
>> What do you guys think?
>>
> 
> Ok so to summarize the rest of the thread a bit:
> - The technical advantage is questionable.
> - We might have a non-MMX user out there somewhere.
> 
> As far as the trouble to do this... it's really none. Just change the
> flags in makepkg.conf and the change rolls out as packages get rebuilt.
> 
> I guess I'll start a thread on the bbs for starters, and see if anyone
> is using a pentiumpro anymore.

Is there someone out there with a processor with big MMX tasks who can't 
buy a faster computer and who is likely to benefit?

I guess I'm not in favor of spending our time thinking about this or 
changing it unless we can point to at least one person who actually has 
an itch we'd be scratching. Otherwise, the change could always introduce 
some new problem, and why incur that extra work unless there's an 
existing problem we're solving?

In a similar vein: Does anyone have statistics on in what ways and how 
much benefit x86_64 brings over i686 on hardware that will support it? 
I've been using processors that support x86_64 for years, but have yet 
to be persuaded that there's appreciable benefit to switching. Even a 
10-20% processing speedup might not persuade me, given how cheap 
processing power is these days.

Note: This is *not* in any way a dig against x86_64. It's a sincere 
invitation to provide actual facts to persuade me and others to use it; 
I suppose I could be missing out on significant benefit.

- P