Re: new laptop: compiling source for i7 CPUs???

[Stefan Monnier <monnier@iro.umontreal.ca>]

> There are considerable price increases with each quite small increase in
> speed-- hundreds of dollars--, but over two or three years I think the extra
> dollars would be worth the performance increase... *IF* there
> is a noticeable performance increase.

The rule of thumb, in general is that a speed increase smaller than
about 30% goes unnoticed.

> This would depend to a large degree upon the code... specifically, if the
> code (OS and apps) makes use of the expanded instruction sets of the more
> expensive CPUs.  Generally the code doesn't, unless gcc/make is configured
> for the particular CPU and then that source is compiled. I've done this in
> the (distant) past and noticed a significant increase in performance over
> the stock executables provided by the distro.

Over time, the "baseline" used by the distros evolves, so by the time
your machine is old, most of its features will be used by the distro.

But don't forget that most of those new features only affect very
specific programs.  Some of them may not even affect any program at all
(e.g. because later improvements in compiler techniques work better than
those hardware assists).  IOW it's largely marketing.


        Stefan