-static const int MAX_BLOCK_SIZE = 16 * 1024; // hard limit
-static const int FUSB_BUFFER_SIZE = 2 * (1L << 20); // 2 MB (was 8 MB)
+static const int MAX_BLOCK_SIZE = 16 * 1024; // hard limit
+static const int DEFAULT_BLOCK_SIZE = 4 * 1024; // fewer kernel memory problems
+static const int FUSB_BUFFER_SIZE = 1 * (1L << 20); // 1MB