const QByteArray SEP = ": ";
const QByteArray NEWLINE = "\r\n";

QMap<QString, QString> m_Values;

void QAmiPropertyMap::convertStr(const QByteArray &str)
{
    QStringList lines = QString(str).split(NEWLINE);
    for(const auto &s : lines) {
        int cutAt = s.indexOf(SEP);
        QByteArray key = s.left(cutAt).toLocal8Bit();
        QByteArray value = s.right(s.length() - cutAt - SEP.length()).toLocal8Bit();
        m_Values.insert(key, value);
    }
}

Elapsed time:    1468 ms
One cycle:   4.893333 ms
Create item:     0.022654 ms
Items:      216
Create count (300x216): 64800