4GB memory

[D. Hugh Redelmeier]

| From: Giles Orr <gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org>

|   Vista was rather
| ungenerous in repartitioning: the machine has a 320GB drive and Vista
| takes up 20GB but when asked to shrink the partition Vista would only
| allow that it could give up 135GB.  Defragging didn't change that.  If
| anyone has suggestions on this I'd be happy to hear them, but that's
| not my main reason for writing.

In the XP days, the swap file was unmoveable.  You could turn off
static swap file allocation and then defrag & shrink, then turn it on
again.  I don't know if this applies in the MS Vista era.

I had to buy MS Vista recovery disks.  I could not boot Vista for
the first time (after owning the machine for ~5 months).  Acer's one
year warranty did not apply to Vista -- that was only 90 days (grrr).
It turns out that under some conditions Vista won't boot if you fiddle
with the MBR, which, of course, installing Linux does.  I haven't got
the measure of this problem.  Perhaps it is only the first boot that
won't work.

| I bought the machine with 4GB of memory (4 sticks of 1GB).  I wasn't
| surprised to see Vista displaying 3.2GB, although it amuses me to no
| end that you need 2GB to run it decently and you can't use more than
| 3GB ... that's a pretty small window of opportunity.

According to Wikipedia's article on PAE
  http://en.wikipedia.org/wiki/Physical_Address_Extension
MS Vista SP1 can use PAE to get at all the memory.  So install SP1.

SP1 was not offered by Windows Update until I deleted the
hungry-to-install-itself trial version of Norton
Anti-something-or-other.  Others find some drivers prevent SP1 from
being offered.  If you care, google.

|  But I was
| surprised to find that Debian testing displays very much the same
| thing with "free", 3287MB even after I installed and booted kernel
| 2.6.24-1-686-bigmem.

That is surprising.  If you use dmesg you should see early on what the
kernel thinks the physical memory blocks are.  Here's from my machine:
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000e7000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000003ffc0000 (usable)
 BIOS-e820: 000000003ffc0000 - 000000003ffd0000 (ACPI data)
 BIOS-e820: 000000003ffd0000 - 0000000040000000 (ACPI NVS)
 BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
 BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
 BIOS-e820: 00000000ff7c0000 - 0000000100000000 (reserved)

I use x86-64 on my machines that can handle it.  This hardly ever
causes problems these days, at least in the Red Hat / Fedora / CentOS
world.  I admit that the advantages on a desktop are minor; sane
large-memory handling is one of them.
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists