quick RAM lesson

[gustie]

need to know how much ram each type of system can utilise

XP 32-bit
XP 64-bit

VISTA 32-bit
VISTA 64-bit


im still running XP here 32-bit... but maybe i could save for a new system late next year lol

ALSO can a 64-bit O/S run 32-bit appz? or is EVERYTHING required to be in 64-bit?

ALSO (lol) how much noticable improvement would 64-bit actually show you in normal operation??

cheers!

[stevo1210]

Re: quick RAM lesson

With Windows XP and Windows Vista 32 bit, the maximum RAM amount that it can see (and utilise) is 4GB. Anything higher is not recognised from what I've heard. 64 bit OSs (64 bit XP & Vista) see can see and utilise 4GB of RAM and over.

[dood]

Re: quick RAM lesson

Actually, 32 bit OS's will only see roughly 3.2gb out of 4. I've got 4 gigs installed in my machine here at work, on Vista Business 32bit, and under my computer it claims 3.5GB, and under task manager it claims 3293MB

[Wizard]

Re: quick RAM lesson

appox 3.5GB as Dood stated.

Cheers, Wizard

[gustie]

Re: quick RAM lesson

i see...

cheers for the info


a friend of mine seemed to think it was worth his while using over 4gig on his 32-bit rig.... this would prove it would be pointless


as for 64-bit o/s - can they run 32-bit applications/games etc? or will it only run 64-bit appz

cheers

[gdement]

Re: quick RAM lesson

as for 64-bit o/s - can they run 32-bit applications/games etc? or will it only run 64-bit appz

Never used one, but it shouldn't be a problem. Microsoft has a mechanism for running Win16 apps on Win32, so this should be similar.

As far as speed advantage, I haven't tried it, but it seems it could potentially be significant depending on the programming.
A long time ago I wrote some low-level code for drawing graphics tiles (in DOS). That's a pure memory movement operation, so the 32-bit MOV instruction was much faster than the 16-bit version.
But without reprogramming a 32-bit app isn't going to be any faster on 64-bit windows, because it's still using the same old instructions and 3GB+ of RAM is probably ample.


The gripe I've heard about Windows 64-bit is that there aren't many drivers for it and people generally seem to complain about it in that respect.
I don't think there's much mainstream software that really makes use of 64-bit and it's probably more trouble than it's worth. XP 32-bit is the easiest Windows to live with today.
I'd only recommend 64-bit Windows if you have a specific high-end app that you know will benefit.

[acstech]

Re: quick RAM lesson

I've used XP Pro 64-bit successfully in many customer installations. The key is to do your research. Find out in advance all the hardware, software, and peripherals they're going to use, and make sure they are all 64-bit compatible.

I've noticed XP Pro 64-bit to be generally more responsive and stable than the 32-bit version of XP. Well worth running it if you can get away with it.

[Wizard]

Re: quick RAM lesson

Biggest issue with having 64 bitters is not enough choices of hardware that has drivers that works with 64 bits. And some fo them is buggy.

Cheers, Wizard

[PCBONEZ]

Re: quick RAM lesson

It's not a "Windowz Thing".

32-bit OS's are limited to 4GB because the maximum number of memory addresses a 32-bit address table can hold is 4Gb.

In Widows it shows less than 4Gb because windows *reserves* ADDRESSES for use by device drivers in the same address table as the 'working RAM'.
It's not that the RAM isn't present. It just has no address.

Kind of like a working phone with no number in the phone book (address table).
There's no phone number (address) because the book only has so many lines (4GB worth) but some of those lines are *reserved* for the police and fire department (device drivers).

Addresses for system hardware use start at 4 GB and number down.
[How many are needed will depend on the devices in the system.]
Addresses for OS and user use start at 0 GB and number up.

When(if) the numbers going up collide with the numbers going down that's when you have no more address.
That's usually anywhere from 3.25-3.75 GB for XP.
I saw a Vista 32-bit laptop that ran out at around 2.5 GB because the Vista drivers are so bloated and bulky.
- Boy was the owner that just paid MO $$$ to upgrade from 2GB to 4GB Pissed!
- Paid for 2GB and got 1/2.

Another reason to skip Vista and switch to Linux.....

.

[370forlife]

Re: quick RAM lesson

need to know how much ram each type of system can utilise

XP 32-bit
XP 64-bit

VISTA 32-bit
VISTA 64-bit


im still running XP here 32-bit... but maybe i could save for a new system late next year lol

ALSO can a 64-bit O/S run 32-bit appz? or is EVERYTHING required to be in 64-bit?

ALSO (lol) how much noticable improvement would 64-bit actually show you in normal operation??

cheers!

I run Vista Buisness 64bit, it can run all 32 bit apps, just emulates them in 32bit. You can only support up to 3.5gb of ram.

As for any noticable speed difference, windows will load quicker, so will actual 64bit programs, otherwise 32bit apps are pretty much the same.

As for the amount of ram the OS supports, as PCBONEZ said, its not a windows thing. He explained it well, and if you take 2^32= ~3.2GB. So with a 64bit os, the ceiling is about 10 trillion times larger, about 17.2 billion Gigabytes, or 16.8 million terabytes. I think 64 bit os's will be around for a while.

[dood]

Re: quick RAM lesson

Another reason to skip Vista and switch to Linux.....

.

YEAH!!! So you can have hardware with no driver support at all. Rock!

[PCBONEZ]

Re: quick RAM lesson

YEAH!!! So you can have hardware with no driver support at all. Rock!

Just like Vista.... LOL

[gustie]

Re: quick RAM lesson

wow thanks

so 64-bit can top on 8gig ram or more?

and while emulating will the emulation run to the lower 4gig 32-bit rule or can it use more??

[jpdoe]

Re: quick RAM lesson

Hi, Gustie and 370forlife
@37forlife: I'm sorry to correct you, but 2^32=4Giga. You can verify this using the calculator included with windows. Make sure you have it on "Scientific mode" (on the View menu, choose "Scientific"), and input 2, press the "x^y" button and then input 32 and press enter.

So a 32bit cpu should be able to address the whole 4GB. The oddity of WinXP 32bits seeing less than 4GB of RAM is founded in the way the operating systems are implemented. I didn't research the subject, but I don't think linux 32 bit is gonna be any different.

I don't remember the exact nomenclature, but the thing is, when implementing a modern operating system, you have to divide the addressable memory space in two parts: kernel (OS) memory and user memory. On the NT4 days, for the IA32 architecture they divided the RAM in half: 2GB for kernel memory, and 2GB for system memory.

Let's make one thing clear: When talking about this separation, they were not talking of real memory (that is, on the NT4 days, you didn't have the insane memory prices of today... 4GB of RAM was something reserved for dreams). We're talking architecture here. The OS designer studies what the IA32 architecture gives him to work with, and he sets de foundations of how the OS will work.

But this is really implemented this way. Let's remember that this is all VIRTUAL memory, that will later be directed to system RAM. So if you have 512MB of RAM installed, most of it will be addressed as part of the 2GB of user memory, and a small part (maybe 50MB?) of it will be addressed as part of the 2GB of kernel memory. The swap file will also be addressable by part of this 4GB of addressable space.

As RAM prices went down and the real world system RAM increased, they had to review these design decisions. Once you had more than 2GB of real ram installed, the extra RAM above 2GB couldn't be used to hold user RAM, so it would go to waste. So they modified NT4 to work with 3GB of user RAM and 1GB of kernel RAM.
That's as far as we got when I was studying this. I guess later on, when they had to deal with 3GB RAM systems, they tweaked the design once more.

And since we're on the subject, let's remember Bill Gates inmortal worlds: "640KB should be enough for anyone"

[PCBONEZ]

Re: quick RAM lesson

The 64-bit address table can theoretically support 16 exabytes but the address table isn't the limiting factor anymore.
For example MS puts in 'admin limits' on their OS's for marketing reasons.

MS XP-x64 -- 128 GB
MS Vista Home 64-bit -- 8 GB
MS Vista Home Prem 64-bit -- 16 GB
MS Vista Bus/Ent/Ult 64-bit -- 128 GB
MS 2003 Ent Itanium -- 1 TB
MS 2003 Std x64 R2 -- 32 GB
MS 2003 Ent x64 R2 -- 2 TB
OS X -- 4 TB
RH Ent Linux ES ver 3 -- 8 GB
RH Ent Linux ES ver 4 -- 16 GB
RH Ent Linux base ver 5 -- 16 exabytes
RH Desktop Linux v5 -- 4 GB
RH Desktop v5 w/ wkstn -- 16 exabytes

Supposed platform (CPU) limits for RH v5
x86 -- 16 GB
Itanium2 -- 1 TB / 1024 TB
x86-64 -- 256 GB / 1 TB
Power -- 512 GB / 1 TB
zSeries -- 64 GB

The chipset used may also impose limits.

This isn't new stuff.
Server class boards that support 64Gb and up have been around for a while.

.

I don't know where memory is allocated from when using an emulator.
I imagine the 'real' OS controls that but it might depend on the specific programs involved.

If 32-bit programs will run on 64-bit the OS has to support 32-bit as a legacy function. I don't know which ones do and don't off the top of my head. Just check out any you are considering with google.

.

[PCBONEZ]

Re: quick RAM lesson

Supermicro considers these EOL [End of Life] products.
http://www.supermicro.com/products/m...20/X6DHE-G.cfm
http://www.supermicro.com/products/m...20/X6DH8-G.cfm

[willawake]

Re: quick RAM lesson

if 32bit is emulated does this mean it run slower?

[acstech]

Re: quick RAM lesson

YEAH!!! So you can have hardware with no driver support at all. Rock!

Maybe in 2002...

[dood]

Re: quick RAM lesson

Just like Vista.... LOL

I do not use or advocate the use of Vista. XP works great for me

I've tried various Linux versions, and I'd love to be able to settle on one and use it instead of Windows. But, the sticking point is drivers that aren't included in the box. Not only that (as Windows has the same problems), but installing drivers is not as easy as it is in Windows. I've never had to drop to a command prompt to install a driver in Windows (well, at least not since Win98 or so).

I love Ubuntu and Kubuntu, but until I can install it and easily get my wireless card in my laptop working, I'll pass.

[PCBONEZ]

Re: quick RAM lesson

I don't use Vista or XP on my own gear.
Never did.
I got off the MS Bandwagon at W2k.
-
Good thing too.
There's no brakes, no steering, it's been all down hill since, and I see a cliff ahead.

.