FYI: dell xps 13 (2015 model) compilation times (i5, FullHD)

[Christian Lohmaier]

Hi *,

somewhat OT, but I was asked by different people about my experience
with the Dell XPS 13..

So I thought I'd share some numbers...
* how long does a LO build take on the machine (I have the i5 model
with the FullHD screen)
  201min for a "time CCACHE_RECACHE=1 make gb_COLOR=1"
$ ccache -s
cache directory                     /home/cl/.ccache
cache hit (direct)                     0
cache hit (preprocessed)               0
cache miss                         15624
called for link                      776
called for preprocessing            1198
multiple source files                  2
compile failed                       382
preprocessor error                    79
bad compiler arguments               186
unsupported source language            8
autoconf compile/link               1173
unsupported compiler option          364
no input file                        511
files in cache                    242828
cache size                          26.4 Gbytes
max cache size                      30.0 Gbytes

* full from-scratch build using the created ccache: 16min
$ ccache -s
cache directory                     /home/cl/.ccache
cache hit (direct)                 15539
cache hit (preprocessed)              67
cache miss                            18
called for link                      776
called for preprocessing            1198
multiple source files                  2
compile failed                       382
preprocessor error                    79
bad compiler arguments               186
unsupported source language            8
autoconf compile/link               1173
unsupported compiler option          364
no input file                        511
files in cache                    242914
cache size                          26.4 Gbytes
max cache size                      30.0 Gbytes

* can you do a full build on battery?
  nope, it runs out of  juice after 3h of full-throttle use, so you
get close, but not-quite to the finish line.
Mo 5. Okt 10:34:56 CEST 2015
Battery 0: Discharging, 100%, 17:13:29 remaining
Thermal 0: ok, 33.0 degrees C
Thermal 1: ok, 33.0 degrees C
Thermal 2: ok, 25.0 degrees C

Mo 5. Okt 13:20:39 CEST 2015
Battery 0: Discharging, 4%, 00:07:06 remaining
Thermal 0: passive, 82.0 degrees C
Thermal 1: active, 82.0 degrees C
Thermal 2: ok, 25.0 degrees C

ccache -s
cache directory                     /home/cl/.ccache
cache hit (direct)                     0
cache hit (preprocessed)               0
cache miss                         14737
called for link                      467
called for preprocessing            1198
multiple source files                  2
compile failed                       382
preprocessor error                    79
bad compiler arguments               186
unsupported source language            8
autoconf compile/link               1173
unsupported compiler option          364
no input file                        511
files in cache                    260658
cache size                          27.9 Gbytes
max cache size                      30.0 Gbytes

you might get a full build if you provide external cooling and disable
wifi and bluetooth and tweak some settings.

* how long does the battery last?
  as seen above: depends: the 100% estimate of 17h is nor
representative (as you want to use the laptop with the screen on, and
not just having it sit around idling doing nothing), and neither is
the 3h (as you're unlikely to do full-from-scratch-LO builds while
only on battery. With screen on low brightness, and doing
webbrowsing/email and some light development,  getting somewhere
around 9h is realistic though.

HTH,
ciao
Christian