Is 64 bit computing ready for the desktop? a.k.a. The Story of Me and My Laptop David North

Can represent integers roughly from 2-64 to 264 What is 64 bit? CPU capable of dealing with 64-digit binary numbers (as opposed to 32 bit, last 15 years) Can represent integers roughly from 2-64 to 264

Why should I care? Breaking 4 GB memory barrier 64 bit addresses allow us to support memory up to 16.8 million TB (realistically, physical limitations currently mean 32GB is the top)

Other advantages Memory-mapped files for faster disk access – 4gb DVD images, etc Security: fewer, if any, viruses and exploits for 64 bit platforms

Lack of application availability, esp for 64 bit Windows The downsides Lack of application availability, esp for 64 bit Windows Lack of device drivers Same data takes up more space in memory than on 32-bit (swollen pointers, alignment padding) Hence increased mem reqs of a process => implications for processor cache efficiency

What's out there? AMD were first to make a mass-marked 64 bit architecture for desktops/laptops: the AMD64, used in some Athlon and Opterons, and later the Turion Intel eventually followed with the EM64T, used in the latest Pentiums and Xeons

A case study: me and my laptop [on the server: 64 bit is go, has been for over a year] Bought a 64 bit laptop (with AMD64 processor) in June 2006 It came with 32 bit Windows XP Should I install a 64 bit OS? 64 bit Windows: sheer lack of software, expensive 64 bit Linux!

March 2007: Ubuntu 64 Sheer lack of packages in the repositories Flash, Realplayer totally borken Not much help in the forums, because nobody was using it Fail. Back to 32 bit.

April 2008: Try again Much better: nearly every package you can think of is there Flash, Realplayer took some hacking, but were doable Not much difference in speed from 32 bit, day-to- day Fixed some driver issues, introduced others

This isn't a problem for most people... Downsides? Compilers/interpreters may now use 64bit integers, which could mess up some programs, e.g. The Oberon Compiler This isn't a problem for most people...

Conclusion

Questions?