SCIENTIFIC-LINUX-USERS Archives

October 2011

SCIENTIFIC-LINUX-USERS@LISTSERV.FNAL.GOV

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Stephan Wiesand <[log in to unmask]>
Reply To:
Stephan Wiesand <[log in to unmask]>
Date:
Mon, 17 Oct 2011 18:50:17 +0200
Content-Type:
text/plain
Parts/Attachments:
text/plain (26 lines)
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

ATOM RSS1 RSS2