Variable LZX window sizes

[wimlib] / doc / imagex-optimize.1.in

diff --git a/doc/imagex-optimize.1.in b/doc/imagex-optimize.1.in
index 4f3832c494c20275f78016e5009b18ab34d8f21f..c1cf5cb1290a0ea004e526f6340b6558fd09a9b4 100644 (file)
--- a/doc/imagex-optimize.1.in
+++ b/doc/imagex-optimize.1.in
@@ -47,6 +47,16 @@ compression about twice as slow and will increase the compression ratio by maybe
 Recompress the WIM file using the specified compression type.  \fITYPE\fR may be
 "none", "fast", or "maximum".  This implies \fB--recompress\fR.
 .TP
+\fB--chunk-size\fR=\fISIZE\fR
+Set the WIM compression chunk size to \fISIZE\fR.  Using this option is not
+recommended because WIM chunk sizes other than the default of 32768 are not
+supported by Microsoft's software.  But if you decide to use this option
+regardless, you can choose a chunk size that is any power of 2 greater than or
+equal to 2^15 (32768) up to 2^21 (2097152) for LZX ("maximum") compression or
+2^26 (67108864) for XPRESS ("fast") compression.  Larger chunks mean larger LZ77
+dictionaries and better compression ratios on sufficiently large files, but
+slower random access.
+.TP
 \fB--threads\fR=\fINUM_THREADS\fR
 Number of threads to use for compressing data.  Default: autodetect (number of
 processors).  This parameter is only meaningful when \fB--recompress\fR is also