All measurements are done "hot", i.e. :

* `sccache` loaded with up-to-date files.
* RAM loaded with open files being used as cache.
  * "No ME, No `sccache`" `yosys` build might be missing some files loaded into RAM on Windows.
* CPU caches possible still loaded with binaries (do OSes bother to purge `mmap`ped exes from all levels of cache when they exit?).

All builds are clean builds. The Linux machine is from mid-2017, Intel Core i7-6700 w/ 32GB RAM. The Windows machine is from late-2011, Intel Core i7-2760QM (I _think_) w/ 16GB RAM.

# Litex

Command: `time python3 -m litex_boards.targets.1bitsquared_icebreaker --cpu-variant lite`

|OS     |environment        |real     |user     |sys     |
|-------|-------------------|---------|---------|--------|
|Windows|ME, No `sccache`   |2m50.828s|0m0.000s |0m0.015s|
|Windows|ME, No `sccache`   |3m5.253s |0m0.000s |0m0.015s|
|Windows|ME, `sccache`      |3m8.480s |0m0.000s |0m0.015s|
|Windows|No ME, No `sccache`|1m49.087s|0m0.000s |0m0.015s|
|Windows|No ME, `sccache`   |1m53.482s|0m0.015s |0m0.015s|
|Linux  |No `sccache`       |0m24.605s|0m50.616s|0m9.965s|
|Linux  |`sccache`          |0m13.626s|0m6.222s |0m2.808s|

# Yosys

Command: `time make -j8 PREFIX=/mingw64` (Windows) or `time make -j8 PREFIX=$HOME/.local` (Linux)

`Makefile.conf` (`ENABLE_SCCACHE` possibly commented out):

Windows:

```
CONFIG := msys2-64
# ENABLE_PLUGINS := 0
ENABLE_SCCACHE := 1
ENABLE_GHDL := 1
GHDL_PREFIX := /mingw64
```

Linux:

```
CONFIG := gcc
ENABLE_SCCACHE := 1
# ENABLE_DEBUG := 1
```

|OS     |method             |real      |user      |sys      |
|-------|-------------------|----------|----------|---------|
|Windows|ME, No `sccache`   |14m37.986s|1m2.164s  |2m43.992s|
|Windows|ME, `sccache`      |7m4.253s  |1m4.437s  |2m54.094s|
|Windows|ME, `sccache`      |6m22.656s |1m0.193s  |2m43.038s|
|Windows|No ME, No `sccache`|13m16.959s|0m59.355s |2m38.572s|
|Windows|No ME, `sccache`   |3m34.495s |1m1.070s  |2m40.987s|
|Linux  |No `sccache`       |3m15.235s |23m25.033s|0m52.930s|
|Linux  |`sccache`          |0m13.115s |0m8.405s  |0m1.642s |