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
