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Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

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Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#51

Post by masklinn »

AD1066 wrote: post #29

Holy Baader-Meinhof phenomenon. I ordered 8 GB of RAM for my HP laptop last night and spent well over two hours reading about this exact subject to see if I needed to install Windows 64-bit when it arrives. I think I even stumbled upon this same page. That being said, I still don't fully understand; Once I install the new RAM, will I only receive the benefits if I perform a new 64-bit install of Windows 7, or will up…

> Once I install the new RAM, will I only receive the benefits if I perform a new 64-bit install of Windows 7

That is correct, the alternative is to use a ($1000+) Server edition, some of which do give access to >4GB in 32b.

If you put 8GB RAM in a laptop running a 32b non-server Windows, you'll simply see 4GB.

You may see very small improvements nonetheless due to dual-channel activating (when pairing identical sticks of RAM, the CPU is able to "talk" to both at the same time rather than one at a time, doubling bandwidth), but I rather doubt it. The gains are usually insignificant. And you won't get any gains from actually increasing the amount of RAM in the machine.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#52

Post by cdr »

thechut wrote: post #23

I dual boot Ubuntu 12.04 32-bit and Windows 7 32-bit on my HP laptop, it has 8GB of RAM. When I am running Ubuntu I see 7.8GB (I'm assuming this is 1000 vs 1024 issue and doesn't concern me) in my system settings and resource monitor. When I am running Windows I only see 3.8GB of RAM in resource monitor, but I see the full 8GB if I look in device manager. Can somebody explain this to me?

You might be interested to know that Windows keys don't discriminate between 32-bit/64-bit. If you can find installation media for the same type of x64 distribution (Home, Pro, etc) as your 32-bit, you can install x64 and use your current key. May be worth the reinstall to get access to your RAM.

Of course, you might make sure that appropriate drivers for your laptop exist for x64. I would hope any laptop that can accommodate 8GB would have x64 drivers.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#53

Post by nivertech »

riffraff wrote: post #26
nivertech wrote: post #21

Earlier quoted context omitted.

x32 is useful for VM-based languages: Java, Python, Ruby, Erlang, etc.

I am not sure this is true generally: the JVM has been able to use "Compressed OOPS" aka 32bit pointers to objects managed by the VM in 64 bit platforms for a few years, even without any support from the OS.

Off course it's better when language/VM implementer take this issue into account, but for those who doesn't, just building a VM/interpreter for x32 architecture can be the only workaround.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#54

Post by j_s »

virmundi wrote: post #14

This seems like an appropriate place to ask this question. At work I have an i5 with 8 GB of ram. Unfortunately we're stuck with XP 32. So is there a away for me to use more memory over all? Specifically I have to have Outlook and my VirtualBox Linux machine running at the same. I'd like to use bank switching or PAE to give my VM 4 GB. While all of the other applications just fight out for the remaining 4.

Run VMWare vSphere on the bare metal, virtualizing both XP and Linux. Of course, you'd have to re-install everything.

http://www.vmware.com/products/vsphere-hypervisor/faq.html

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#55

Post by [deleted] »

virmundi wrote: post #14

This seems like an appropriate place to ask this question. At work I have an i5 with 8 GB of ram. Unfortunately we're stuck with XP 32. So is there a away for me to use more memory over all? Specifically I have to have Outlook and my VirtualBox Linux machine running at the same. I'd like to use bank switching or PAE to give my VM 4 GB. While all of the other applications just fight out for the remaining 4.

[deleted]

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#56

Post by keithpeter »

virmundi wrote: post #25
masklinn wrote: post #22

Earlier quoted context omitted.

Technically, all modern Windows versions have PAE enabled (the NX bit requires enabling PAE for instance), but Windows adds license-based memory restrictions on top of that. That's how the 2GB limit on Starter, the 4GB limit on non-server and the various limits on server editions are implemented. And there is a kernel hack/patch to lift that restriction, although it is of course fully unsupported: http://superuser.co…

Thanks for the info. It's sad that I out my employer will allow it.

would employer allow a linux install then XP in a VM or several? All problems solved then.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#57

Post by glhaynes »

sp332 wrote: post #31
0x0 wrote: post #20

Earlier quoted context omitted.

Sure. But after the porting work has been done by the distribution vendor, it's done. The package manager software should be able to do whatever is necessary to almost transparently ensure any necessary dependencies are installed for the required sub-architecture. So I would imagine that in most cases, end-users won't notice any hassle except having the option to choose between x32 and x86_64 per package during insta…

OK, modulo taking up extra space on already-cramped CD distros, taking more time to download updates, taking up more space on production hard disks, and having to download a new version of the software if your dataset grows over 4GB, it sounds good. :)

And extra memory taken up at runtime by having to load the other versions of the libraries. And the I/O costs of reading them in. I'd think that'd outweigh the performance benefits many times over in nearly all cases.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#58

Post by mbell »

ralish wrote: post #39

Most of the responses to the question seem to be "sort of" correct but missing important parts of the overall picture. Further, a complete answer to the question is going to be subject to the operating system the given application is running under as the specifics are going to be heavily dependant on OS implementation. I can't speak for Unix systems, but on the Windows side, it's complicated and messy: PAE (Physical…

> So if at all possible, avoid 32-bit, 64-bit is the solution; PAE, AWE & 4GT were only ever workarounds.

PAE isn't a workaround, and is mandatory for x86-64 when operating in long (64bit) mode as it is still how the CPU addresses physical memory.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#59

Post by rogerbinns »

ajross wrote: post #8
0x0 wrote: post #6

There is also a very recently developed middle ground, the Linux "x32" ABI, since Linux v3.4: http://en.wikipedia.org/wiki/X32_ABI As I understand it, this mode gains performance by sticking with 32bit pointers in user-space instead of 64bit pointers, while still allowing for taking advantage of all the new registers etc available in x86-64 ("amd64") CPUs. (Many programs doesn't really need more than 4gb virtual addr…

x32 is clearly a good technical solution. If you're running on a 64 bit kernel, x32 is superior to i686 in every measurable way. But it's also yet another architecture. It's not binary compatible with either i686 or x86_64. You need your whole userspace compiled to use it. Middleware with embedded assembly (there's a surprising amount of this in glibc, and of course things like ffmpeg, libjpeg, etc...) needs to be po…

Note that there is no need to port every single program. You can still run a 64 bit userspace (or a 32 bit one for that matter), but for the apps where there is a major benefit use x32. This also means you don't have to port every library etc.

Re: Can a 32-bit OS machine use up all 8GB RAM + 20GB page file?

#60

Post by codex »

ajross wrote: post #8
0x0 wrote: post #6

There is also a very recently developed middle ground, the Linux "x32" ABI, since Linux v3.4: http://en.wikipedia.org/wiki/X32_ABI As I understand it, this mode gains performance by sticking with 32bit pointers in user-space instead of 64bit pointers, while still allowing for taking advantage of all the new registers etc available in x86-64 ("amd64") CPUs. (Many programs doesn't really need more than 4gb virtual addr…

x32 is clearly a good technical solution. If you're running on a 64 bit kernel, x32 is superior to i686 in every measurable way. But it's also yet another architecture. It's not binary compatible with either i686 or x86_64. You need your whole userspace compiled to use it. Middleware with embedded assembly (there's a surprising amount of this in glibc, and of course things like ffmpeg, libjpeg, etc...) needs to be po…

True, but it's the future. Eventually no distro will ship i686 code anymore, just as they don't ship i386 code anymore.
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