c# - ZipArchiveMode.Update never completes for very large files -

i have code, zipfilename existing zip file, sourcefile file want compress, , filename archive entry name.

            using (ziparchive archive = zipfile.open(zipfilename, ziparchivemode.update))             {                 await task.run(() => archive.createentryfromfile(sourcefile, filename, compressionlevel.fastest));             } 

this works great small files, no larger 50kb. these, file compressed archive no problem. can add many small files want way.

but large files 1.8gb in size, memory consumption shoots several gb, , file never compresses archive.

how can better handle compressing large files existing destination archive? note need use existing destination zip / archive file, , must .zip.