What is average lantency?

[Edandlindz28]

I am looking replace my internal HD and looking at all the different brands, I think I am just going with a 5400 RPM but what is the difference on the average lantency? Some are 5.5ms and others 4.2ms. Noticable? There is this one I found that I thought was a good price:
TOSHIBA MK1234GSX 120GB 5400 RPM Serial ATA150 Notebook Hard Drive - OEM

The only thing is I don't know if I should go with one that has a better warrenty like WD or Seagate.

 

[JFreak]

It's more like 14-15ms on the 5400rpm hard drive. 7200rpm hard drive latency is about 10-11ms and the difference *is* noticeable between the two.

5ms latency is like a 15krpm SCSI hard drive meant for servers or high-end workstations. You won't find one in consumer laptops any day soon.

EDIT: I recommend the Seagate 7200rpm 160GB for any laptop.