Windows XP and RAM limitations

stevenrw · May 28, 2009, 07:21:39

I'm looking to increase the RAM on my XP home machine. I've been told that the 32bit version of XP Home will only recognise up to 2 gb of RAM. To get any benefit from doubling it to 4Gb I need to change the OS to XP Pro 64 bit.
Anybody heard of this one? I'm reluctant to pay out for 64bit XP (which will cost much more than the memory upgrade of course) then have to upgrade again in a couple of years when the replacement for the sorry mess that is Vista becomes a realistic proposition.

Glenn · May 28, 2009, 07:44:31

Steve, a 32bit OS can address approximately 3.2 - 3.5Gb of ram. 64 bit XP is available http://www.kikatek.com/product_info.php?products_id=29037&source=froogle not sure if that is the correct version though

kinmel · May 28, 2009, 08:31:37

Glen is correct, an explanation on RAM and Windows XP is given by H.P.

You can download the PDF file

Sebby · May 28, 2009, 09:08:27

I would just install 3GB in total and that should be fine, rather than going for the 64-bit version of XP.

stevenrw · May 28, 2009, 09:33:31

I was thinking along those lines also Sebby. Seems that having to spend maybe £75 on an OS just to get 1GB more RAM in isn't logical especially given the likely lifespan remaining in XP.
However, assuming I do stick with my existing XP home and put in 3gb, will I still get benefit from the Mobo's dual channel architecture? That's more to do with data processing througput to/from the cpu than available RAM isn't it?

Glenn · May 28, 2009, 09:40:53

XP's offical support is now to 2014 for retail and business versions.

Rik · May 28, 2009, 09:42:32

Is that support in terms of help, or support in terms of updates, Glenn?

gizmo71 · May 28, 2009, 09:53:01

Quote from: stevenrw on May 28, 2009, 09:33:31
However, assuming I do stick with my existing XP home and put in 3gb, will I still get benefit from the Mobo's dual channel architecture? That's more to do with data processing througput to/from the cpu than available RAM isn't it?

If you add 2x512M to the existing (presumably) 1x1G you should still get dual channel - check your mobo details but normally you only need matched pairs.

TBH you might as well add 2x1G and ignore the fact that .5-.8G won't be used.

Rik · May 28, 2009, 09:56:01

I agree, Giz, the extra cost is usually minimal.

stevenrw · May 28, 2009, 10:05:21

Just to be clear then, assuming the board has 4 slots, 4x1gb sticks with the 32bit OS will give me the "bonus" of using the Dual channel feature where I will "Lose" perhaps 0.8gb I will still see better processing speed than with just 3 sticks. As you say, RAM is only about £15/gb nowadays.
Either way that's got to be more economic than buying a new OS. Who knows, maybe the new one will have some magic to recognise more ram anyway?
Sadly there does seem to be a hit on latency reported using 1gb sticks over 512's but them's the breaks I suppose.

Rik · May 28, 2009, 10:07:39

You've got it.

Sebby · May 28, 2009, 11:28:44

Quote from: stevenrw on May 28, 2009, 10:05:21
Just to be clear then, assuming the board has 4 slots, 4x1gb sticks with the 32bit OS will give me the "bonus" of using the Dual channel feature where I will "Lose" perhaps 0.8gb I will still see better processing speed than with just 3 sticks. As you say, RAM is only about £15/gb nowadays.
Either way that's got to be more economic than buying a new OS. Who knows, maybe the new one will have some magic to recognise more ram anyway?
Sadly there does seem to be a hit on latency reported using 1gb sticks over 512's but them's the breaks I suppose.

Correct, except you could use 2x1GB sticks and 2x512MB and still benefit from dual channel.

stevenrw · May 28, 2009, 12:34:54

Thanks guys for your input. Accurate and timely as always.
Much appreciated.

john · May 28, 2009, 13:41:22

This may make things clearer : http://members.shaw.ca/bsanders/WindowsGeneralWeb/RAMVirtualMemoryPageFileEtc.htm

Rik · May 28, 2009, 14:42:34

Bring back QEMM I say.

Sebby · May 28, 2009, 14:48:24

Had to look that one up! For those that are interested:

http://en.wikipedia.org/wiki/QEMM

Rik · May 28, 2009, 14:57:55

Every boy had a copy back in the day, Seb.

Sebby · May 28, 2009, 14:59:53

Rik · May 28, 2009, 15:06:11

Dealers used to look at you askance if you asked for 1MB of RAM back then, they saw it as wasteful.

Sebby · May 28, 2009, 15:17:41

Well, given that Bill Gates said we'd only need 640kb, it would have been considered wasteful.

Rik · May 28, 2009, 15:28:41

That really was the attitude at the time, Seb. Indeed, I can remember some incredulity at Adobe when a user built a machine with a gig of RAM, about 15 years ago, and Photoshop fell over because of it. Times certainly change.

kinmel · May 28, 2009, 16:23:41

Quote from: Rik on May 28, 2009, 15:06:11
Dealers used to look at you askance if you asked for 1MB of RAM back then, they saw it as wasteful.

I remember having to drive all the way to Shire Hall for a meeting with the I.T. Dept because we needed an IBM PC-AT with 1 meg of RAM to run some Canadian vehicle routing software.

Rik · May 28, 2009, 16:26:20

Happy days, Alan, where we used to be byte misers and software was smaller and more efficient.

kinmel · May 28, 2009, 16:30:03

Quote from: Rik on May 28, 2009, 16:26:20
Happy days, Alan, where we used to be byte misers and software was smaller and more efficient.

The good old days Rik, when 64k was considered over the top, the ZX81 came with 1K and you could upgrade to 16K ! It is amazing what was achieved with those old computers

Rik · May 28, 2009, 16:35:40

It was, Alan. I can remember coding in assembler to make it faster and smaller. I used to burn apps onto EPROMs for the Beeb. Writing in BASIC, all variable names were skinned down to save space, and the number of concatenated lines of code were painful. It didn't make for good reading, but every byte counted.