Include information about the benchmark output/methodology
Addresses #930
diff --git a/programs/zstd.1.md b/programs/zstd.1.md
index eea6854..9e4c5d3 100644
--- a/programs/zstd.1.md
+++ b/programs/zstd.1.md
@@ -258,6 +258,9 @@
* `--priority=rt`:
set process priority to real-time
+**Output Format:** CompressionLevel#Filename : IntputSize -> OutputSize (CompressionRatio), CompressionSpeed, DecompressionSpeed
+
+**Methodology:** For both compression and decompression speed, the entire input is compressed/decompressed in-memory to measure speed. A run lasts at least 1 sec, so when files are small, they are compressed/decompressed several times per run, in order to improve measurement accuracy.
ADVANCED COMPRESSION OPTIONS
----------------------------