缓冲区的增量如何影响下载速度？

Question

我有以下代码可从互联网上下载

 URLConnection    ucon = url.openConnection();
 InputStream is = ucon.getInputStream();
 BufferedInputStream inStream = new BufferedInputStream(is, 8192);//this is value one 
 FileOutputStream outStream = new FileOutputStream(new File(location));
 byte[] buff = new byte[8192];//this is value two 

 int len;

 while ((len = inStream.read(buff)) != -1) {
     outStream.write(buff, 0, len);          
 }

我的问题是如果我更改缓冲区值会发生什么：值1和2 下载速度如何变化？他们应该是相同的价值吗？如果它们不相同，它们应该表示什么？

我已阅读以下帖子：

How do you determine the ideal buffer size when using FileInputStream?

但我真的不明白。有人可以为我解释吗