I have set of compressed JPG2K files (https://imap.maryland.gov/Pages/imagery-download.aspx) that I have been converting to IMG. IMG has proven to have 4x faster rendering. The only issue is we have limited HDD space and the IMG aerial files are ~approximately 10x larger.
From what I've read uncompressed files are faster since GeoServer doesn't have to unpack the files. We would like to do some experimenting on compression levels and see if the performance is comparable to IMG.
So for my questions: Would decreasing compression provide any performance increase? Or does the level of compression make no difference to GeoServer?