C++ bootstrap of GCC - still useful ?

[Laurent GUERBY]

On Sun, 2011-07-10 at 20:03 +0200, Toon Moene wrote:
> On 07/10/2011 06:45 AM, Ian Lance Taylor wrote:
> 
> > Toon Moene<toon@moene.org>  writes:
> 
> >> As of a couple of months, I perform a bootstrap-with-C++
> >> (--enable-build-with-cxx) daily on my machine between 18:10 and 20:10
> >> UTC.
> >>
> >> I see that the build by a C++ compiler has been the subject of the GCC
> >> Gathering at Google:
> >>
> >> C++ style and migration   crowl    writing and using C++ in gcc
> >>
> >> It is not quite clear what the outcome of this discussion was.
> >>
> >> Is there still interest in daily builds like mine ?
> >
> > Yes, it's definitely useful.
> >
> > The immediate blocker to using C++ in gcc is the Ada frontend.
> > --enable-build-with-cxx and --enable-languages=ada do not work together.
> 
> Ah, OK.
> 
> Just drop me a note when a regular test including Ada starts to be 
> useful (I probably have to skip some other front end language in favor 
> Ada to stay within the two hour elapsed time window between two weather 
> forecasting runs).
> 
> BTW, the ultimate reason I asked was that it turned out that running an 
> ordinary quad core PC to the max doesn't come for free.
> 
> Last month I got past year's electricity bill - it turns out that I am 
> now (16 hours of weather forecasting and 4 hours of GCC bootstrapping 
> per day) using 3200 KWh a year - to the tune of 1100 Euros.
> 
> So the question whether a run is useful is certainly relevant :-)

Hi,

Since I pay the electricty bill of some compile farm machines
I understand you here :).

New generation of hardware has made significant progress on energy
efficiency: my latest built PC is a Intel core i7 2600 4 cores 8 threads
3.4 GHz 4x4 GB of RAM with 40 GB SSD + 2TB HDD, 80+ gold PSU and it
idles around 30W and uses 110W full CPU load. PC cost is around 800 EUR
in France (19.6% VAT included). 

According to your data it should reduce your bill by a factor of three
(365W => 110W), so it should pay itself in around a year: 720 EUR less
on your yearly electricity bill, assuming you counted only your PC power
consumption in your figures. And bonus nearly no noise in a case with 2
or 3 120mm fans.

I haven't had a chance to test AMD A8 processors but I will do soon.

Sincerely,

Laurent