Be Warned !! The AMD64 implementation on the HP laptops, Zv6000 and the Compac equiv, the R4000 have one channel of memory disabled. In short, they do not use the dual channel memory configuration. It is not fixable and causes about a 10 to 17 percent loss of productivity. Also know that the laptop, despite what some hero's will tell you, only runs pc2700 memory reliably. It will NOT run PC3200 memory very well. There is a websit, zv6000forums.com that is devoted to the zv6000/r4000 laptop and is a very good site for information. I have a ZV6000 with the 3500+ AMD64 and am quite happy with it. This laptop, with only one memory channel still renders Carrara and Terragen almost twice as fast my P4 2.6 gig system. HP has a system now with the Turion core, I do not know if dual channel memory has been crippled on it or not.