diff --git a/weed/command/mount.go b/weed/command/mount.go
index 6165402b4..661ddfe06 100644
--- a/weed/command/mount.go
+++ b/weed/command/mount.go
@@ -37,7 +37,7 @@ func init() {
 	mountOptions.collection = cmdMount.Flag.String("collection", "", "collection to create the files")
 	mountOptions.replication = cmdMount.Flag.String("replication", "", "replication(e.g. 000, 001) to create to files. If empty, let filer decide.")
 	mountOptions.ttlSec = cmdMount.Flag.Int("ttl", 0, "file ttl in seconds")
-	mountOptions.chunkSizeLimitMB = cmdMount.Flag.Int("chunkSizeLimitMB", 4, "local write buffer size, also chunk large files")
+	mountOptions.chunkSizeLimitMB = cmdMount.Flag.Int("chunkSizeLimitMB", 16, "local write buffer size, also chunk large files")
 	mountOptions.cacheDir = cmdMount.Flag.String("cacheDir", os.TempDir(), "local cache directory for file chunks")
 	mountOptions.cacheSizeMB = cmdMount.Flag.Int64("cacheCapacityMB", 1000, "local cache capacity in MB")
 	mountOptions.dataCenter = cmdMount.Flag.String("dataCenter", "", "prefer to write to the data center")