Question

What is the best memory buffer size to allocate to download a file from Internet? Some of the samples said that it should be 1K. Well, I need to know in general why is it? And also what’s the difference if we download a small .PNG or a large .AVI?

Stream remoteStream;
Stream localStream;
WebResponse response;

try
{
    response = request.EndGetResponse(result);

    if (response == null)
        return;

    remoteStream = response.GetResponseStream();

    var localFile = Path.Combine(FileManager.GetFolderContent(), TaskResult.ContentItem.FileName);
    localStream = File.Create(localFile);

    var buffer = new byte[1024];
    int bytesRead;

    do
    {
        bytesRead = remoteStream.Read(buffer, 0, buffer.Length);
        localStream.Write(buffer, 0, bytesRead);
        BytesProcessed += bytesRead;
    } while (bytesRead > 0);
}

Answer 1

Use at least 4KB. It’s the normal page size for Windows (i.e. the granularity at which Windows itself manages memory), which means that the .Net memory allocator doesn’t need to break down a 4KB page into 1KB allocations.

Of course, using a 64KB block will be faster, but only marginally so.