oxipng — oxipng.exe -o 6 --libdeflater --threads 1 --alpha --strip all

file insize instate stats outsize outstate savings
lorem.png 135614 bytes /c2 /f0 /n63
Kernel  Time =     0.015 =    0%
User    Time =     1.953 =   99%
Process Time =     1.968 =  100%    Virtual  Memory =     23 MB
Global  Time =     1.959 =  100%    Physical Memory =     22 MB
105679 bytes /c2 /f0 /n16 29935 bytes
lorem_90.png 483089 bytes /c2 /f0 /n106
Kernel  Time =     0.015 =    1%
User    Time =     1.500 =   98%
Process Time =     1.515 =   99%    Virtual  Memory =     22 MB
Global  Time =     1.518 =  100%    Physical Memory =     18 MB
451970 bytes /c2 /f0 /n56 31119 bytes
lorem_big.png 127451 bytes /c2 /f0 /n3
Kernel  Time =     0.015 =    0%
User    Time =     1.875 =  103%
Process Time =     1.890 =  104%    Virtual  Memory =     21 MB
Global  Time =     1.817 =  100%    Physical Memory =     18 MB
68797 bytes /c0 /f0 /d8 /n26 58654 bytes
lorem_big_16.png 65084 bytes /c0 /f0 /d8 /n28
Kernel  Time =     0.031 =    1%
User    Time =     1.796 =  100%
Process Time =     1.828 =  101%    Virtual  Memory =     19 MB
Global  Time =     1.793 =  100%    Physical Memory =     20 MB
46626 bytes /c0 /f0 /d8 /n12 18458 bytes
lorem_big_17.png 65551 bytes /c0 /f0 /d8 /n35
Kernel  Time =     0.015 =    0%
User    Time =     1.812 =  101%
Process Time =     1.828 =  101%    Virtual  Memory =     19 MB
Global  Time =     1.794 =  100%    Physical Memory =     19 MB
45954 bytes /c0 /f0 /d8 /n13 19597 bytes
lorem_big_noise.png 823706 bytes /c2 /f0 /n82
Kernel  Time =     0.031 =    0%
User    Time =     7.796 =   99%
Process Time =     7.828 =   99%    Virtual  Memory =     37 MB
Global  Time =     7.870 =  100%    Physical Memory =     38 MB
613790 bytes /c2 /f0 /n59 209916 bytes
lorem_gray.png 140439 bytes /c2 /f0 /n123
Kernel  Time =     0.015 =    1%
User    Time =     0.968 =  103%
Process Time =     0.984 =  104%    Virtual  Memory =     16 MB
Global  Time =     0.940 =  100%    Physical Memory =     15 MB
56668 bytes /c0 /f0 /d8 /n6 83771 bytes
lorem_image.png 133069 bytes /c2 /f0 /n3
Kernel  Time =     0.031 =    0%
User    Time =     3.187 =   99%
Process Time =     3.218 =  100%    Virtual  Memory =     34 MB
Global  Time =     3.201 =  100%    Physical Memory =     32 MB
117411 bytes /c2 /f0 /n33 15658 bytes
lorem_noise.png 542244 bytes /c2 /f0 /n67
Kernel  Time =     0.015 =    0%
User    Time =     3.625 =   99%
Process Time =     3.640 =   99%    Virtual  Memory =     25 MB
Global  Time =     3.641 =  100%    Physical Memory =     22 MB
428159 bytes /c2 /f0 /n84 114085 bytes
lorem_pal.png 121950 bytes /c2 /f0 /n73
Kernel  Time =     0.015 =    1%
User    Time =     0.937 =  101%
Process Time =     0.953 =  102%    Virtual  Memory =     16 MB
Global  Time =     0.926 =  100%    Physical Memory =     15 MB
51835 bytes /c0 /f0 /d8 /n6 70115 bytes
total savings 651308 bytes
total time 25,46 seconds