Confused about Vista 32 bit memory support

[Severian]

I have a question. I am thinking of upgrading my PC and am wondering about whether I should install 32 or 64 bit Vista. I keep reading everywhere that 32 bit Vista only supports 3GB of RAM, and since the PC I was thinking of buying has 4GB or RAM, I would need 64 bit Vista to get the best out of it.

 

However, I am confused as to why a 32 bit operating system should only support 3GB of RAM.

 

1GB is 1024³B=2³⁰B while a 32 bit operating system should be able to handle 2³²B=4x2³⁰B=4GB. So why are we losing the extra GB?

 

By my calculation the 32b operating system should just be able to handle 4GB of RAM.

[insane_alien]

some memory addresses are reserved for things like the PCI bus and operating system usage. thats why you can't access the full 4GB.

 

its asically a relic from when 32-bit addresses were so far ahead of the times a few wwasted addresses were no big deal. there is a kernel option in linux to allow a 32-bit kernel to access more than 4GB of RAM but there is some performance loss along with it. not sure if vista can do the same.

 

i'm also not sure what the software compatability situation is with 64-bit vista.

[Pangloss]

That's my understanding as well. XP had the same problem.

 

If it's any help, you will probably be able to run 64-bit Vista just fine. It runs most 32-bit programs. The main issue there is drivers. Check and see if all the ones you need are available in 64-bit versions before you upgrade, and if that's the case I would say go ahead and do it. We've run it extensively at our school and have had only minor application compatibility issues thus far. (For example, a program used to broadcast the computer's image data to a projector via IP address instead of direct cable doesn't run under 64-bit Vista yet, though the manufacturer has promised it this quarter.) We run mainly Maya (a 3d rendering/design program) and the Adobe application suite (Photoshop, etc) on those machines. We also run it on some of our laptops.

 

One useful fallback is to throw a (free) copy of Virtual PC 2007 on there and put a WinXP image in it. I've been using that approach for Visual Studio 2005 because of its Vista incompatibilities and I have my students run it that way in their classroom (on the 64-bit Vista machines). I'll probably upgrade to Visual Studio 2008 this term and abandon VirtualPC, because it's a bit slower than the "real" OS (it never allocates more than one thread at a time!), but you may find it useful for running old, incompatible programs.

[foodchain]

Its because of binary code, I have always hated that stuff:D

 

I use a 64 but I cant really see any measurable difference in operation from various other computer systems I have used. I was interested in the 64 just to see what difference on that scale it would have really on the rest of software, and hardware overall. I also don’t know anything about vista as I view software with contempt in general, even some gaming interfaces appear obnoxious to me. Does the vista support for 64 actually mean anything, or is it a marketing ploy?

[insane_alien]

it means it can utilize 64-bit processors more effectively and speed up certain operations.

 

this is particularly noticable in A/V editing.

[foodchain]

it means it can utilize 64-bit processors more effectively and speed up certain operations.

 

this is particularly noticable in A/V editing.

 

 

I have a pretty industry standard computer with a amd 64 running in it. I play online games in which I have no support in terms of a graphics card for instance. I get a decent frame per second or fps and can compete with duel core 32 bit intel chips and graphics cards. This though I find hard as to understand exactly what and if any impact having a 64 bit pc versus a 32 bit provides. I mean even if you strip out all the various programs that an OS or personal computer may be running, how do you get down to what impact a 64bit cpu has on modern gaming? I mean have any advances come in regards to motherboards really for the 64 such as the north or Southbridge chipsets for this reason or any real reason save just to be able to land a 64bit cpu on a motherboard and have it at least function? As far as ultimate gaming experiences go these days I think duel core intel pretty much owns the market really. I know amd is releasing a mulit core strategy that is also geared towards gaming but I have not heard much about it.

[insane_alien]

well, 64-bit can handle complex calculations on large data sets better. meaning it will improve data throughput meaning you can have better effects and stuff on the stuff that isn't handled by the graphics card which have been 64-bit and beyond for a long time. most have multiple hundred bit data buses.

[foodchain]

well, 64-bit can handle complex calculations on large data sets better. meaning it will improve data throughput meaning you can have better effects and stuff on the stuff that isn't handled by the graphics card which have been 64-bit and beyond for a long time. most have multiple hundred bit data buses.

 

 

 

Right so you are saying that a 64 bit processors main advantage would simply be the ability to execute larger programs based on the hardware? Or simply that it will have more functionality with that hardware based on available space on the pc for such in some form? That’s basically what I am getting down to. Microsoft of course historically have all been built for a 32 bit environment, as such I would imagine that a great deal of advance in hardware and software is around 32 bit. 64 such as the athlon is still somewhat new, as in having how many standard operating systems built around 64 bit cpus? So I just don’t understand I guess the test bench for what exactly and where is the impact of using a 64 bit processor over a 32 bit one in the real world?

 

I am more on the hardware point of things because I am thinking of building my own computer using various vendors. I want to make a 64 bit based system in regards to the cpu, so I am trying to find out all I can about the best way to optimize a single 64 bit cpu with modern hardware such as a motherboard. This then of course would equate into the operating system of choice in which your options are not plentiful so I don’t understand again the glorious reality of 64 bit cpu based computing yet.

[insane_alien]

Microsoft of course historically have all been built for a 32 bit environment

 

ROFL windows 95 - Me were 16-bit OS's with a bit of 32-bit added on. the NT kernel line has been true 32-bit.

 

http://en.wikipedia.org/wiki/64-bit <just read here.

 

basically 64-bit is to 32-bit what 32-bit was to 16-bit computers.also, 64-bit has been around since 1961 so its hardly new. the only new thing is that its used in desktops now.

[foodchain]

ROFL windows 95 - Me were 16-bit OS's with a bit of 32-bit added on. the NT kernel line has been true 32-bit.

 

http://en.wikipedia.org/wiki/64-bit <just read here.

 

basically 64-bit is to 32-bit what 32-bit was to 16-bit computers.also, 64-bit has been around since 1961 so its hardly new. the only new thing is that its used in desktops now.

 

 

who cares about windows 95? Can you even use that on the internet?

 

The current OS I run has no support really for my cpu(64) that I know of, when I bought it that was just the way it was. Now Microsoft, makers of the blue screen of death just to remind you says it has some new operating system for the 64. With modern desktop being 32 bit really, in concentration and in time on a computer timeline, what and how do you know the advances of the 64 bit cpu with various applications? would volume of information processed in a unit of time be the only real means to do that? Please elaborate?

[bascule]

However, I am confused as to why a 32 bit operating system should only support 3GB of RAM.

 

1GB is 1024³B=2³⁰B while a 32 bit operating system should be able to handle 2³²B=4x2³⁰B=4GB. So why are we losing the extra GB?

 

Long ago OS developers discovered a wacky solution that proved useful for a variety of circumstances.

 

If a program attempts to access memory which doesn't exist, a page fault is triggered. This executed the BIOS's page fault handler. However, an OS could substitute any page fault handler they so desired. And thus virtual memory was born...

 

Today virtual memory is a little more elegant than that... CPUs now include a memory management unit (in protected mode it prevents programs from writing into each other's address space). It can be used for many other nifty things, such as swap or memory mapped IO: write to an address in memory, and the data will be written out somewhere completely different. It could be a file. It could be an entirely different piece of hardware (memory map the Linux framebuffer device, for instance, and you can draw directly into it by writing to RAM).

 

But, there's a price: Those virtual addresses eat up address space that can be used by physical RAM. That upper megabyte is reserved for all sorts of memory mapped IO operations between various peripherals in your computer and the OS. And depending on what devices you have you may not even be able to get 3GB... video RAM will be mapped into the system address space, meaning if you have some fancy pants 512MB video card, you'll lose 512MB of address space that could've been used for physical RAM.

[Severian]

Thanks for the clarification. I will make sure I get a 64 bit operating system then.

 

One more question. If I buy the full version of Vista Home Premium I only get the 32-bit version in the box. However, I can send away for the 64-bit version for an extra $10 (basically shipping costs).

 

Does anyone know if this is also true for the Vista Home Premium Upgrade? Can I still send away for the 64-bit version with the upgrade box, or will I need to buy a full version?

 

Another question. I am also seeing offers like this, for "system builders". Does anyone have any experience with this? This looks exactly what I am after (i.e. already 64-bit) but I wouldn't want to do anything illegal, or indeed buy something which turned out to be no use to me. However, it looks like the only difference is that there is no support included, which would be fine since I have always found MS support to be useless anyway.

[Pangloss]

I'm afraid I don't know about upgrade trade-ins for 64-bit. You might have to try some other forums but perhaps someone here will know.

 

That version you linked looks like a license only -- no disc. If you already have a 64-bit Vista disc (of any version) that should be fine. They put all the different flavors of Vista on the same DVD, as I understand it, though you still have to make sure it's a 64-bit vs a 32-bit DVD.

 

(Also the OS is fully installed now, so there's no need to copy over the i386 folder (in fact there is no i386 folder on the disc), and you don't have to worry about keeping a copy of the installation disc. It's still a good idea for repair/recovery purposes, but you can just copy the DVD -- it's the license that matters, although again I add the disclaimer "as I understand it".)

[Severian]

To answer my own questions, I just had a look at the upgrade box in a shop and indeed it does say that you can send off for the 64-bit version and pay only for shipping. So I could indeed just buy the upgrade disk and still get the 64-bit version.

 

As for the OEM, I think it does include the disk, just not the support (which is only for 3 months in retail anyway) and no manual. Also you can't transfer it to another computer. I found some details here. Since I never use their support anyway I think I will buy the OEM 64-bit version directly.