[Interest] Qt 6 is much more faster to compile from source

Thiago Macieira thiago.macieira at intel.com
Tue Sep 7 19:50:25 CEST 2021

On Tuesday, 7 September 2021 02:52:49 PDT Tor Arne Vestbø wrote:
> Good to hear!
> Part of it comes from CMake generating ninja files instead of Makefiles.

Our qmake-generated Makefiles weren't that slow. Nothing compared to Automake, 
at least.

Qt 5 qtbase/src build:
Build succeeded, took 3:01.027s (total run time 3:01.027s), 2388.2% CPU usage

Qt 6 equivalent with Ninja:
Build succeeded, took 222.01s (2385% CPU usage)

3:01.027 = 181.027s (sorry, different wrapper, so they print time differently)

Same compiler, same otherwise-idle machine, icecc disabled. The configuration 
on both builds is meant to be the same, full build.

Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel DPG Cloud Engineering

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