Низкая скорость загрузки через WebClient

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If BackgroundWorker1.IsBusy = True Then
            Exit Sub
        Else
            BackgroundWorker1.RunWorkerAsync()
        End If
        ProgressBar1.Visible = True
    End Sub
 
    Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        Dim Client As New Net.WebClient
        Dim Tmp As String = Client.DownloadString("http://ip-address.ru/show")
        Label1.Text = Tmp
        Client.Dispose()
    End Sub
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Label1.Text = ""
        CheckForIllegalCrossThreadCalls = False
         ProgressBar1.Visible = False
        ProgressBar1.Style = ProgressBarStyle.Marquee
    End Sub
 
    Private Sub BackgroundWorker1_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
        ProgressBar1.Visible = False
    End Sub
End Class

WebBrowser1.Navigate("http://ip-address.ru/show")

 Label2.Text = WebBrowser1.DocumentText

        Dim wc As New WebClient
        Dim s = wc.DownloadString("http://ip-address.ru/show")
        MsgBox(s)

 Dim Client As New Net.WebClient
        Dim Tmp As String = Client.DownloadString("http://ip-address.ru/show")
        Label1.Text = Tmp
        Client.Dispose()

 Client.Proxy = New System.Net.WebProxy