I'm building a new box , based on an Asus M2A-VM mobo (old , but I'm
familiar with it , already have 2 in use) and a quad-core AMD Phenom
processor . I'm planning on loading a 64 bit XP Pro alongside probably
Ubuntu 16-04 . I'm wondering if the Ubuntu has the same limitation of 3Gb
usable RAM that 32 bit versions of Windows has . Anybody know ?
No , it's a limitation of Windows XP 32 bit OS's - I'm not sure if this
limitation applies to other versions of Windows . It will only recognize 3
Gb of RAM , the 64 bit version will recognize up to (I think) 8 Gb . The
"new" motherboard came with 4 Gb installed , along with an Athlon X2
processor (speed unknown) which will be banked as a spare . My plan is to
install that quad core and bump it to 8 Gb of RAM , see if I can get better
performance than this desktop .
"Terry Coombs" wrote
| > It is a limitation of 32 bits, applies more or less equally to any OS.
| Thanks , I did download a 64 bit version of Ubuntu 16-04 LTS earlier just
| in case .
More specifically, it's a limitation in addressing.
Stored data in RAM is stored at a memory "address".
Those addresses are critical and ubiquitous in
system functions. To send or receive data from the
system an address pointer is often required. A 32-bit
OS uses a 32-bit "long" integer for those pointers.
It's a 32-bit OS because a 32-bit/4byte integer is
the common currency for data.
So the limitation is simply that a number can't be
specified beyond about 4 billion. There's no way to
point to data stored in RAM at the 5 billionth byte.
Allowing for some sharing of RAM for graphics, that
often works out to about 3.2 GB addressable RAM.
On Saturday, September 10, 2016 at 9:23:26 AM UTC-4, Mayayana wrote:
While it's true that 32 bit addressing thing is the root cause,
it's not true that it's impossible to have more than 4GB
of RAM because of it. All Intel CPUs since the Pentium II have
supported more than 4GB of physical memory, it had a 36 bit
address bus. The instruction set works with 32 bit addresses,
32 bit data, but the addresses get mapped by the MMU into a physical
memory address space of 64GB. OS's that support virtual memory can
take advantage of it, if the OS designers choose to do so.
On Saturday, September 10, 2016 at 10:48:15 AM UTC-4, songbird wrote:
That MB almost certainly supports more than 4GB, the documentation
would make it clear. Sounds like Terry thinks it does. Now whether
Linux supports 4GB+, IDK, because I don't know anything about Linux.
Yes , the motherboard will support up to 8Gb of RAM . I've got 2 other
computers that use this motherboard , it does what I want to do . Will
support up to 4 monitoer with an added card , 2 onboard outputs , one VGA
and a DVI-D , 6 channel sound with jack sensing . I have dome to believe my
complaints about slowness are due to web content that is more aimed at the
newer multi-core processors . In that respect this board should do well
enough with a quad core processor and more RAM - and a 64 bit OS .
On Saturday, September 10, 2016 at 9:49:26 PM UTC-4, Terry Coombs wrote:
As an experiment, did you try just doing a clean install of the OS?
I'd bet that your abysmal performance is a result of what eventually
seems to happen to all PCs, regardless of how many cores they have,
which is that either stuff winds up getting installed, or parts of
the OS somehow get corrupted, or something happens that we don't
even understand, that severely impacts the performance.
Every PC I've had, after several years, if I just put it back to the
original factory software, there was a significant increase in
performance. In fact, I bet half the boost in performance people
think they are getting from a new PC they could have gotten by just
re-installing the software on their old one. IDK what kind of web
content really benefits from all those cores, call me skeptical.
On Saturday, September 10, 2016 at 10:31:53 PM UTC-4, trader_4 wrote:
Actually, I guess you will be able to easily do the experiment
because you are doing clean installs, you're using the same MB and
you intend to just replace the CPU with the faster one at the end,
right? So, you should be able to do some testing to see how much
improvement you get with a clean OS, how much more with the new CPU.
I think you also had less than 4GB of RAM? That would be a factor too.
I would think all your planned improvements would give a boost, but
the fact that you seemed to have really terrible performance now
leads me to believe that something is screwed in the software, more
so than the CPU being the problem. If you take some time measurements
of how long it takes to boot, how long it takes to pull up some common
web pages, etc, before and after, it will be interesting if you post
32-bit x86 Linux will also support more than 4GB of RAM, as long as you use
a kernel with support for PAE mode. Not all distros are continuing to
support 32-bit x86 though, many are concentrating on 64-bit
x86_64 since that's what the majority of users will want.
"Bud Frede" wrote
| 32-bit x86 Linux will also support more than 4GB of RAM, as long as you
| a kernel with support for PAE mode. Not all distros are continuing to
| support 32-bit x86 though, many are concentrating on 64-bit
| x86_64 since that's what the majority of users will want.
Interesting report here:
Also this, explaining that PAE support was in XP,
but conflicted with some drivers:
It's not enough for the OS to support it.
It seems a more relevant question is what people
need the RAM for. I usually work on XP-32 and have
no problems with RAM. Someone editing video, on
the other hand, might see a very big difference with
a 64-bit system and lots of RAM. The point being
that 64-bit capacity is still mainly preparation for
the future and not needed for most software usage
today. Given that, PAE seems like a dubious hack,
especially given that Terry Coombs is only trying to
improve web browser behavior, which likely has little,
if anything, to do with his hardware.
Given how inexpensive RAM is, I'm not sure I see a downside to using a
64-bit OS at this point. In addition, 64-bit mode on the CPU brings with
it some useful features, and it also means that some 32-bit malware no
I personally use far more than 4GB of RAM on a regular basis, mainly to
PAE may not add anything useful for the person trying to improve web
browser behavior, but I don't know that I'd call it a "dubious hack"
since it evidently _was_ useful in many situations.
As for XP having issues with PAE, I'd probably lean towards it being
more of a problem with Windows than with PAE itself. MS has never put
much emphasis internally on solid code or squashing bugs.
"Bud Frede" wrote
| I'm not sure I see a downside to using a
| 64-bit OS at this point.
No. I don't know why he's looking for 32-bit Linux.
The only notable downside I know of is that 32-bit
Windows shell extensions can't run. Anything 32-bit
can't run in a 64-bit process. That means shell
extensions, COM DLLs, ActiveX controls, etc. Which
is why IE32 is needed for ActiveX. Most ActiveX controls
are 32-bit. So there can be some minor complications
moving to 64-bit, but I don't think they'd affect most
| PAE may not add anything useful for the person trying to improve web
| browser behavior, but I don't know that I'd call it a "dubious hack"
| since it evidently _was_ useful in many situations.
For what? How many software programs need more
than 2 GB RAM? Maybe a video editor? That would
probably be running on 64 bit, anyway. Meanwhile,
the PAE is creating instability and may be incompatible
with some drivers. I can't see it being relevant.
| As for XP having issues with PAE, I'd probably lean towards it being
| more of a problem with Windows than with PAE itself. MS has never put
| much emphasis internally on solid code or squashing bugs.
See the Wikipedia link. It was a problem
with incompatible drivers. I don't entirely
understand how it works, but it sounds like
32-bit software that wants to use PAE would
need to be PAE-aware, PAE-designed, and
would need to check that Windows is PAE-
enabled. So it gets back into the same boat:
How often would it be relevant for a 32-bit
program to be rewritten with bigger numeric
data types just so that it can take advantage
of 4+GB RAM addressing? Probably never.
On Monday, September 12, 2016 at 6:07:43 PM UTC-4, Mayayana wrote:
He isn't, he never said that in the original post, he has even said
that he downloaded the 64 bit version. Good grief.
PAE doesn't create instability if you use it properly. Just because
some OS's, eg Windows consumer ones, didn't use it doesn't mean that
it couldn't be done or is inherently hard to do.
It works as part of the virtual memory capability built into Intel
32 bit CPUs since the 386.
but it sounds like
Only the OS needs to know.
So it gets back into the same boat:
Apparently a lot of software developers believe there is a
benefit, as they are issuing 64 bit versions of apps. The ones
that would benefit are any that need to handle data arrays
that are bigger than 4GB. It's certainly not your email
reader, but there are apps that do manipulate large data sets.
And you should probably take up your "not needed" concerns
with cell phone makers. They are currently moving to 64 bits.
Mon, 12 Sep 2016 22:06:33 GMT in alt.home.repair, wrote:
The 64bit explorer doesn't support 32bit extensions and has no way to
natively execute them. you'd need to run the 32bit explorer to make use
of 32bit extensions. OR, upgrade said extensions to 64bit so the 64bit
version of explorer can make use of them. Explorer in this sense not to
be confused for IE, although they still have some things in common.
As far as 'real 32bit programs', 64bit Windows can run them, via
emulation. Ironically, your 64bit AMD/Intel processor (Non Itanium)
doesn't need emulation to run 32bit; as they're backwards compatable and
can do it natively.
MID: <nb7u27$crn$ email@example.com>
Hmmm. I most certainly don't understand how I can access a copy of a
Are you installing a 32-bit Linux on a 64-bit processor? The Phenom
should have the PAE flag:
I run 32-bit at work because of the hassles of compiling our software
on 64. It's not that big of a deal but otoh going to 64 bit doesn't buy
me much. However I run 64 bit SuSE at home. Years ago 64 bit drivers for
Linux could be problematic but that has changed.
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