[Interest] Faster Qt app build

[Mike Jackson]

You are comparing a Quad Core i5 to a Dual Core i5. So the Quad should 
be faster than the dual core. If you really want to compare them a bit 
better, on the Quad core tell JOM to only use 2 threads, and on the Dual 
core, if you are using "make" as your build system, ensure you are 
sending the -j2 or -j argument to make otherwise make will only build 
using a single process/cpu/core.

The SSD comparison is probably a wash. You do not state what year the 
MacBook Pro is so I don't know if the SSD is SATA or PCIe based. Either 
way the MacBook Pro SSD should be as fast as the 840 EVO drive.


-- 
Mike Jackson  [mike.jackson at bluequartz.net]


Nuno Santos wrote:
> For Mac/iOS applications Qt uses clang (sorry for the misunderstanding)
> For Android build Qt uses GCC
>
> My main dev machine is a Macbook 13 Retina i5 2.5 dual core with a stock SSD drive
> The Windows machine I refer has a i5 2.5 quad-core with a Samsung 840 PRO SSD drive
>
> I bought the 840 PRO because it is known for it’s incredible performance.
>
> Compiling the exact same program on the windows machine is at least twice fast as on the mac machine. MSVC vs CLANG.
>
> Do you guys think this is only due to the drive? Isn’t it taking advantage of the extra cores on Windows? Also, on mac, it doesn’t seem to be taking advantage of the multiple cores.
>
> Question: passing -jX argument does anything or not?
>
> Regards
>
> Nuno
>
>> On 21 Oct 2016, at 19:06, Mike Jackson<imikejackson at gmail.com>  wrote:
>>
>> Hmm,
>>   That does not seem correct? I have never seen a Windows build of anything go faster on Windows than on Linux or macOS give those are running on the exact same hardware.
>>
>> And when you state "GCC" builds are you using GCC from MacPorts, Homebrew or somewhere else? because Apple has not shipped GCC (at least a recent version) in a long time.
>>
>> --
>> Mike Jackson  [mike.jackson at bluequartz.net]
>>
>>
>> Nuno Santos wrote:
>>> Hi,
>>>
>>> On Windows, building a Qt app is blazing fast. It seems that jom takes the cpu cores to it’s maximum power.
>>>
>>> On Mac the GCC builds are really slow and passing the -jX argument doesn’t seem to make any difference. Is there a way to speed up builds? My projects have a lot of files now and compiling a build can take around 5 minutes on a i5 2.5 dual core CPU.
>>>
>>> Any tips?
>>>
>>> Thanks!
>>>
>>> Regards,
>>>
>>> Nuno Santos
>>> Founder / CEO / CTO
>>> www.imaginando.pt
>>> +351 91 621 69 62
>>>
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>