Change default block fraction to 2.0

read.c

@@ -60,7 +60,7 @@ static void tar_write_last(void);
 #pragma mark DECLARE READ BUFFER
 
 #define STREAMSIZE (1024 * 1024)
-#define MAXSPLITSIZE (64 * 1024 * 1024) // xz -9 blocksize
+#define MAXSPLITSIZE ((64 * 1024 * 1024) * 2) // xz -9 blocksize * 2
 
 static pipeline_item_t *gRbufPI = NULL;
 static io_block_t *gRbuf = NULL;

write.c

@@ -16,7 +16,7 @@ struct io_block_t {
 
 #pragma mark GLOBALS
 
-double gBlockFraction = 1.0;
+double gBlockFraction = 2.0;
 
 static bool gTar = true;