There is no straight answer to this question.
All latency seconds depend on individual configs of any laptop. I run a W7/64 on a Sony FW41ZJ with 6 GB of RAM on 6 ms and a brand new Vaio Z model (W7/64 6 GB) with 12 ms to get the same performance. Both clean DJ only installs with all useless software put off with MSConfig, no wireless, bluetooth and anti virus on and so one.