def METHOD_NAME(disk, timeout, num=5):
    results = 0
    for i in range(num):
        cmd = params["device_cache_read_cmd"] % disk
        (s, output) = session.cmd_status_output(cmd, timeout)
        if s != 0:
            test.fail("Fail to perform device/cache read"
                      " timings \nOutput is: %s\n" % output)
        test.log.info("Output of device/cache read timing check (%s of %s):",
                      i + 1, num)
        for line in output.strip().splitlines():
            test.log.info(line)
        (result, unit) = re.findall("= *([0-9]*.+[0-9]*) ([a-zA-Z]*)",
                                    output)[1]
        if unit == "kB":
            result = float(result) / 1024.0
        results += float(result)
    return results / num