On Oct 17, 2011, at 18:20 , Yasha Karant wrote: [...] > Now I have a decision to make: IA-32 SL 6.1 or X86-64 SL 6.1 . The > processor will support X86-64, but the machine only has 4 Mbyte of RAM as > delivered (upgradeable to 8 Mbyte -- but this is a cost) -- which is only 0.5 > Mword in X86-64 64 bit mode. The hard drive is 500 Gbyte SATA at 5400 RPM -- > not a high performance unit.
I guess we're talking Gigabytes of RAM here, not Megabytes? > There is no special need for 64 bit work on the machine that primarily is an > end-user linux workstation: web browser (including use of university services > only available through such an interface), IMAP email client, OpenOffice, > various LaTeX interfaces, some display of video, use of Linux VirtualBox to > use MS Win (for which the unit is licensed) to use a MS Win only application, > but no development or programming -- and the ability for a skilled end user > under Network Manager to connect to whatever 802.11 WAP that is available > without my intervention. > > Thus, my feeling is to stay with the IA-32 environment. Any thoughts to the > contrary? Yes: The 32-bit kernel will leave 25% of your 4 GB RAM unused, I believe. And all processes will be confined to 3 GB of address space (even if purely virtual). Increasingly, new features are only made available by TUV for the 64-bit flavour (KVM, xfs, samba3x on SL5, pNFS). Since the Java and Flash plugins are now available as 64-bit builds, much of the hassle with running 64-bit SL is now history. x86-64 has a future, ia32 IMHO hasn't (x32 seems interesting but will take a while to arrive and will use a 64-bit kernel). The extended register set and faster PC-relative addressing are not available to ia32 applications. A 500GB disk is plenty for installing the .i686 packages alongside the 64-bit ones. That being said, staying with ia32 may still be slightly more convenient, and part of the 1 GB of real memory you gain with x86-64 will be consumed by 64-bit pointers/longs and alignment. Choose your poison ;-) HTH, Stephan -- Stephan Wiesand DESY -DV- Platanenenallee 6 15738 Zeuthen, Germany