[En-Nut-Discussion] Off-topic - Building Nut/OS fast...very fast

[Ulrich Prinz]

> 
>> Parallel builds with processors with serveral cores scales nearly linear
>> even on normal disk , e.g. for the linux kernel or a wine build on linux. 
>> So pure processing power is all you need first.
>>
>> Does your build setup use several cores?
> 
> As explained in my other replies, this definitely speeds things up.
> 
> Nevertheless, only 3 or 4 cores are utilized up to 10 or 20% when
> running make without -j. I'd expect 1 core at 90%.

Ok, I don't have windows any more but in Linux a build of gcc compiled
with -j5 is bringing all of my 4 cores to ~100%...

I don't have a SSD but use a more silent than fast 2TB WD drive. Ok, the
projects where copied over from an old IDE drive and are therefore not
fragmented. (EXTFS4 should be aware of fragmentation, I hope).
> 
> On a normal disk there is a lot of stepping noise, which implied, that
> this may be the reason for those lazy cores. But the SSD doesn't change
> the situation much.

I fear that the math in the core is the break and not the few transfers
done for some text files. And if windows is not releasing the cores for
full work but requires them to share compilation time with windows tasks...
> 
> The "incredible performance boost of SSD" people are talking about, can
> be observed only when the script creates the initial directory
> structure, this is indeed a lot faster, something like 2s compared to
> 10s. But building takes about 2h instead of 2:15h, comparing SSD to slow
> mechanical drives. So, who cares about 8s?
> 
> 
>>     Harald> The next idea is to get faster RAM. I'm currently using cheap
>>
>> Probably not worth ...
> 
> Ok, seems to the current opinion and saves me some bucks.
> 
Try cygwin instead of the other tools. A simple rm is a big difference
of around 2s MingW/yagarto-tools ro ??ms of cygwin.

And don't ask me why, I needed cygwine once to recompile openocd with
some patches and against FTDIlib instead of libusb, Later I was sick of
those long "make clean" times of nutos and searched C:\ for any other
appearence of rm.exe.
I simply tried PATH=C:\cygwin\bin instead of C:\Programme...\bin and run
make clean all install. It was almost blown of the chair from the speed
make did run...

Ulrich