This is a place where I'll store various benchmarks on lossless PNG compression. While I'm normally okay with stripping metadata chunks on a case-by-case basis in my archiving, these tests are going to revolve around purely lossless compression when possible.
If you're interested in visually lossless (transparency-lossy) compression, another really good benchmark resource (by the author of pingo) can be found here.
Intel i7-6850k 4.3MHz
ZOTAC GTX 980ti AMP! Extreme
32GB DDR4 RAM
Tested using PowerShell's Measure-Command{}
-z -4 -i 25 -f (IMAGE)
-z -4 -i 25 -f (IMAGE)
-b/d/k/f (IMAGE)
-9 --strict -keep --mt-deflate=12 (IMAGE)
-9 --strict -keep --allfilters-b --mt-deflate=12 (IMAGE)
-o7 -preserve (IMAGE)
(IMAGE) --zopfli --threads 12 --interlace 0 --keep=tRNS,gAMA,cHRM,sRGB,iCCP,acTL,fcTL,fdAT,tEXt,zTXt,iTXt,bKGD,pHYs,sCAL,sBIT,sPLT,hIST,tIME,sTER,oFFs,vpAg --preserve
-lossless -s9 -multiblocks=12 -nodate -nostrip (IMAGE)
-ow -brute -reduce -save (IMAGE)
-file:"(IMAGE)" -KeepFileDate -KeepBackgroundColor:K -KeepTextualData:K -KeepFrameControl:K -KeepPhysicalPixelDimensions:K
(IMAGE) (IMAGE) /k1 /kp /kt /y
-o (IMAGE) --ext=.png --force --speed=1 --quality=100-100 -- (IMAGE)
--in=(IMAGE) --out=(IMAGE) --max-evaluations=1 --estimator=libdeflate,level=12 --out-deflate=zopfli,iter=25
/o3 /i0 /g2 /md keep all /t /tz /y (IMAGE)
-m -y --iterations=25 --filters=0meb --keepchunks=tRNS,gAMA,cHRM,sRGB,iCCP,acTL,fcTL,fdAT,tEXt,zTXt,iTXt,bKGD,pHYs,sCAL,sBIT,sPLT,hIST,tIME,sTER,oFFs,vpAg (IMAGE) (IMAGE)
Digital drawing from my friend Kriztian of one of his characters, Aristora.