C#にてファイルダウンロードのレスポンスが遅い。

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// リクエスト生成
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
request.ContentType = REQUEST_CONTENT_TYPE;
request.Timeout = REQUEST_TIMEOUT;
request.CookieContainer = cookieContainer;
request.Proxy = System.Net.GlobalProxySelection.GetEmptyWebProxy();

int errorCode = 0;
Stream inputStream = null;
Stream outputStream = null;
try
{
	//サーバーからの応答を受信するためのWebResponseを取得
	HttpWebResponse response = (HttpWebResponse)request.GetResponse();

	// Streamを取得
	inputStream = response.GetResponseStream();
	outputStream = new FileStream(binaryFilePath , FileMode.CreateNew );

	int i = 0;
	byte[] bytes = new byte[1048576];
	while( (i=inputStream.Read(bytes , 0 , bytes.Length )) > 0 )
	{
		outputStream.Write(bytes , 0 , i);
		this.progressBar.Value += i;
	}
}
catch(Exception e)
{
	throw e;
}
finally
{
	if(outputStream!=null)
	{
		outputStream.Close();
	}
	if(inputStream!=null)
	{
		inputStream.Close();
	}
}

----（抜粋）---------------

<object 
	classid="http:/hoge/hunya.DLL#HogeHogeControl"
	height="240" width="440" VIEWASTEXT>
</object>