Большой обьем текста в CEdit

CString strOutput;
    LPSTR str = LPSTR((DWORD_PTR)WinINIR + m_rawofset);
    strOutput = str;
    m_edit.SetWindowTextW(strOutput);

    ::SetWindowTextA(m_edit.m_hWnd, LPSTR((DWORD_PTR)WinINIR + m_rawofset));

    const DWORD tm = ::GetTickCount();
    ::SetWindowTextA(m_edit.m_hWnd, LPSTR((DWORD_PTR)WinINIR + m_rawofset));
    auto msg = std::to_wstring(::GetTickCount() - tm);
    MessageBox(msg.c_str());

EDITTEXT        IDC_EDIT1,7,7,230,134,ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL | WS_VSCROLL | WS_HSCROLL

void CMFCApplication1Dlg::OnBnClickedButton1()
{
    std::string s = (std::stringstream() << std::ifstream(R"(D:\Y.txt)").rdbuf()).str();
 
    //size_t i = 0;
    //while (s.size() < 8 * 1024 * 1024)
    //{
    //  s += std::to_string(++i);
    //  s += ": ";
    //  for (size_t i = 0; i < 100; ++i)
    //      s += "абвгдежз";
 
    //  s += "\r\n";
    //}
 
    const DWORD tm = ::GetTickCount();
    ::SetWindowTextA(m_edit1.m_hWnd, s.c_str());
    auto msg = std::to_wstring(::GetTickCount() - tm);
    MessageBox(msg.c_str());
}