const int iTestCount = 2000000;
    const int iConcatCount = 5;
    using (new CDisposableTrace("string"))
    {
        for (int j = 0; j < iTestCount; j++)
        {
            string s = string.Empty;
            for (int i = 0; i < iConcatCount; i++)
            {
                s = s + i.ToString();
            }
        }
    }

    using (new CDisposableTrace("StringBuilder"))
    {
        for (int j = 0; j < iTestCount; j++)
        {
            StringBuilder stringBuilder = new StringBuilder();
            for (int i = 0; i < iConcatCount; i++)
            {
                stringBuilder.Append(i.ToString());
            }
            string s = stringBuilder.ToString();
        }
    }