C#

while(true)
{
    // do stuff
}

while (1 == 1)

foreach (DataRow row in DS.Tables[0])
{
    x1.Text = row["test"].ToString();
}

DataTable dt = new DataTable("table1");
DataColumn dc = new DataColumn("col1");
dt.Columns.Add(dc);

for (int i = 1; i < 1000000; i++)
{
    DataRow row = dt.NewRow();
    row["col1"] = "string" + i.ToString();
    dt.Rows.Add(row);
}

long start = DateTime.Now.Ticks;

for (int i = 0; i < dt.Rows.Count; i++)
{
    string s = (string)dt.Rows[i]["col1"];
}

long middle = DateTime.Now.Ticks;

foreach (DataRow r in dt.Rows)
{
    string s = (string)r["col1"];
}

long end = DateTime.Now.Ticks;

TimeSpan forLength = new TimeSpan(middle - start);
TimeSpan foreachLength = new TimeSpan(end - middle);

Console.WriteLine("for = " + forLength.ToString());
Console.WriteLine("foreach = " + foreachLength.ToString());<pre>

Output:
<code>for     = 00:00:00.9079668
foreach = 00:00:00.2661282</code> 

But in the scheme of things, less than a second to process 1000000 records, either way fine by me.

int maxIter=100;  // whatever value makes it take at least 500 msec
for (int pass=0; pass<4; pass++) {
    start timer (or read DateTime.Now.Milliseconds)
    for (int iter=0; iter<maxIter; iter++) {
        code to be timed
    }
    stop timer
    start timer
    for (int iter=0; iter<maxIter; iter++) {
        alternative code to be timed
    }
    stop timer
}