@ktf - whenever I specify CFLAGS or CXXFLAGS environmental variables, I see some of the default optimizations disappear in the makefile such as -O3 and -funroll-loops. I also see they are prepended, so any conflicting flags will be overridden by the defaults
So after messing with compile flags, these seem to get me the fastest encode times. There may be others I haven't tried that might improve things further. Using gcc-11 seemed to have a slight edge over gcc-12. I also have to manually edit the Makefile to remove the -fstack-protector-strong flags.
export CC="/usr/bin/gcc-11"
export CXX="/usr/bin/g++-11"
export CFLAGS="-march=native -O3 -funroll-loops -pipe -flto -fomit-frame-pointer -fno-stack-protector"
export CXXFLAGS="-march=native -O3 -funroll-loops -pipe -flto -fomit-frame-pointer -fno-stack-protector"
export LDFLAGS="-Wl,-s"
./configure --disable-asm-optimizations --disable-altivec
flac v1.3.4 - default Debian build.
time flac -V -8
File-01.wav: Verify OK, wrote 24439771 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24699891 bytes, ratio=0.562
File-03.wav: Verify OK, wrote 39523493 bytes, ratio=0.701
File-04.wav: Verify OK, wrote 40045704 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15922434 bytes, ratio=0.366
real 0m4.398s
user 0m4.144s
sys 0m0.244s
time flac -V -8 -e *.wav
File-01.wav: Verify OK, wrote 24435335 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24662789 bytes, ratio=0.562
File-03.wav: Verify OK, wrote 39491754 bytes, ratio=0.700
File-04.wav: Verify OK, wrote 40039188 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15782279 bytes, ratio=0.363
real 0m10.772s
user 0m10.523s
sys 0m0.240s
time flac -V -8 -p *.wav
File-01.wav: Verify OK, wrote 24419397 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24686505 bytes, ratio=0.562
File-03.wav: Verify OK, wrote 39490413 bytes, ratio=0.700
File-04.wav: Verify OK, wrote 40014362 bytes, ratio=0.817
File-05.wav: Verify OK, wrote 15900707 bytes, ratio=0.366
real 0m9.328s
user 0m9.006s
sys 0m0.316s
time flac -V -8 -e -p *.wav
File-01.wav: Verify OK, wrote 24415349 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24649517 bytes, ratio=0.561
File-03.wav: Verify OK, wrote 39456681 bytes, ratio=0.699
File-04.wav: Verify OK, wrote 40008204 bytes, ratio=0.817
File-05.wav: Verify OK, wrote 15754777 bytes, ratio=0.362
real 1m0.028s
user 0m59.751s
sys 0m0.276s
time flac -V -8 -e -p -b 2304 *.wav
File-01.wav: Verify OK, wrote 24435705 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24730440 bytes, ratio=0.563
File-03.wav: Verify OK, wrote 39359937 bytes, ratio=0.698
File-04.wav: Verify OK, wrote 40034300 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15796351 bytes, ratio=0.363
real 1m15.970s
user 1m15.594s
sys 0m0.376s
time -V -8 -b 2304 *.wav
File-01.wav: Verify OK, wrote 24465811 bytes, ratio=0.728
File-02.wav: Verify OK, wrote 24780187 bytes, ratio=0.564
File-03.wav: Verify OK, wrote 39445204 bytes, ratio=0.699
File-04.wav: Verify OK, wrote 40077690 bytes, ratio=0.819
File-05.wav: Verify OK, wrote 15970568 bytes, ratio=0.367
real 0m4.687s
user 0m4.353s
sys 0m0.320s
time flac -V -8 -A "tukey(5e-1);partial_tukey(2);punchout_tukey(3)" *.wav
File-01.wav: Verify OK, wrote 24439771 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24699891 bytes, ratio=0.562
File-03.wav: Verify OK, wrote 39523493 bytes, ratio=0.701
File-04.wav: Verify OK, wrote 40045704 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15922434 bytes, ratio=0.366
real 0m4.421s
user 0m4.119s
sys 0m0.292s
flac git-0665053c 20221013
time flac -V -8 *.wav
File-01.wav: Verify OK, wrote 24434850 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24616849 bytes, ratio=0.561
File-03.wav: Verify OK, wrote 39438963 bytes, ratio=0.699
File-04.wav: Verify OK, wrote 40041267 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15382115 bytes, ratio=0.354
real 0m4.620s
user 0m4.294s
sys 0m0.292s
time flac -V -8 -e *.wav
File-01.wav: Verify OK, wrote 24431769 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24615103 bytes, ratio=0.561
File-03.wav: Verify OK, wrote 39419532 bytes, ratio=0.699
File-04.wav: Verify OK, wrote 40036367 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15367594 bytes, ratio=0.354
real 0m12.232s
user 0m11.943s
sys 0m0.276s
time flac -V -8 -p *.wav
File-01.wav: Verify OK, wrote 24416121 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24604533 bytes, ratio=0.560
File-03.wav: Verify OK, wrote 39416318 bytes, ratio=0.699
File-04.wav: Verify OK, wrote 40010908 bytes, ratio=0.817
File-05.wav: Verify OK, wrote 15358013 bytes, ratio=0.353
real 0m11.245s
user 0m10.935s
sys 0m0.293s
time flac -V -8 -e -p *.wav
File-01.wav: Verify OK, wrote 24412782 bytes, ratio=0.726
File-02.wav: Verify OK, wrote 24602298 bytes, ratio=0.560
File-03.wav: Verify OK, wrote 39387742 bytes, ratio=0.698
File-04.wav: Verify OK, wrote 40005678 bytes, ratio=0.817
File-05.wav: Verify OK, wrote 15343571 bytes, ratio=0.353
real 1m19.520s
user 1m18.936s
sys 0m0.408s
time flac -V -8 -e -p -b 2304 *.wav
File-01.wav: Verify OK, wrote 24433519 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24697968 bytes, ratio=0.562
File-03.wav: Verify OK, wrote 39305681 bytes, ratio=0.697
File-04.wav: Verify OK, wrote 40031779 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15459132 bytes, ratio=0.356
real 1m45.081s
user 1m44.448s
sys 0m0.416s
time flac -V -8 -b 2304 *.wav
File-01.wav: Verify OK, wrote 24460714 bytes, ratio=0.728
File-02.wav: Verify OK, wrote 24720984 bytes, ratio=0.563
File-03.wav: Verify OK, wrote 39357368 bytes, ratio=0.698
File-04.wav: Verify OK, wrote 40072725 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15503783 bytes, ratio=0.357
real 0m4.857s
user 0m4.491s
sys 0m0.356s
time flac -V -8 -A "tukey(5e-1);partial_tukey(2);punchout_tukey(3)" *.wav
File-01.wav: Verify OK, wrote 24438161 bytes, ratio=0.727
File-02.wav: Verify OK, wrote 24619892 bytes, ratio=0.561
File-03.wav: Verify OK, wrote 39500724 bytes, ratio=0.700
File-04.wav: Verify OK, wrote 40043969 bytes, ratio=0.818
File-05.wav: Verify OK, wrote 15389983 bytes, ratio=0.354
real 0m5.573s
user 0m5.337s
sys 0m0.225s
Compression results. File names appended with version and options used.
ex.. B = -b 2304, A = -A "tukey(5e-1);partial_tukey(2);punchout_tukey(3)"
24412782 File-01.flac-1.4.1-EP
24415349 File-01.flac-1.3.4-EP
24416121 File-01.flac-1.4.1-P
24419397 File-01.flac-1.3.4-P
24431769 File-01.flac-1.4.1-E
24433519 File-01.flac-1.4.1-EPB
24434850 File-01.flac-1.4.1
24435335 File-01.flac-1.3.4-E
24435705 File-01.flac-1.3.4-EPB
24438161 File-01.flac-1.4.1-A
24439771 File-01.flac-1.3.4
24439771 File-01.flac-1.3.4-A
24460714 File-01.flac-1.4.1-B
24465811 File-01.flac-1.3.4-B
33605420 File-01.wav
24602298 File-02.flac-1.4.1-EP
24604533 File-02.flac-1.4.1-P
24615103 File-02.flac-1.4.1-E
24616849 File-02.flac-1.4.1
24619892 File-02.flac-1.4.1-A
24649517 File-02.flac-1.3.4-EP
24662789 File-02.flac-1.3.4-E
24686505 File-02.flac-1.3.4-P
24697968 File-02.flac-1.4.1-EPB
24699891 File-02.flac-1.3.4
24699891 File-02.flac-1.3.4-A
24720984 File-02.flac-1.4.1-B
24730440 File-02.flac-1.3.4-EPB
24780187 File-02.flac-1.3.4-B
43911884 File-02.wav
39305681 File-03.flac-1.4.1-EPB
39357368 File-03.flac-1.4.1-B
39359937 File-03.flac-1.3.4-EPB
39387742 File-03.flac-1.4.1-EP
39416318 File-03.flac-1.4.1-P
39419532 File-03.flac-1.4.1-E
39438963 File-03.flac-1.4.1
39445204 File-03.flac-1.3.4-B
39456681 File-03.flac-1.3.4-EP
39490413 File-03.flac-1.3.4-P
39491754 File-03.flac-1.3.4-E
39500724 File-03.flac-1.4.1-A
39523493 File-03.flac-1.3.4
39523493 File-03.flac-1.3.4-A
56417468 File-03.wav
40005678 File-04.flac-1.4.1-EP
40008204 File-04.flac-1.3.4-EP
40010908 File-04.flac-1.4.1-P
40014362 File-04.flac-1.3.4-P
40031779 File-04.flac-1.4.1-EPB
40034300 File-04.flac-1.3.4-EPB
40036367 File-04.flac-1.4.1-E
40039188 File-04.flac-1.3.4-E
40041267 File-04.flac-1.4.1
40043969 File-04.flac-1.4.1-A
40045704 File-04.flac-1.3.4
40045704 File-04.flac-1.3.4-A
40072725 File-04.flac-1.4.1-B
40077690 File-04.flac-1.3.4-B
48963980 File-04.wav
15343571 File-05.flac-1.4.1-EP
15358013 File-05.flac-1.4.1-P
15367594 File-05.flac-1.4.1-E
15382115 File-05.flac-1.4.1
15389983 File-05.flac-1.4.1-A
15459132 File-05.flac-1.4.1-EPB
15503783 File-05.flac-1.4.1-B
15754777 File-05.flac-1.3.4-EP
15782279 File-05.flac-1.3.4-E
15796351 File-05.flac-1.3.4-EPB
15900707 File-05.flac-1.3.4-P
15922434 File-05.flac-1.3.4
15922434 File-05.flac-1.3.4-A
15970568 File-05.flac-1.3.4-B
43467356 File-05.wav