Microsoft RAM license

[DIYspanner]

I've read that Microsoft only had license for 32bit Windows, such as XP, to allow upto 4GB RAM.


Why would such a license even exist?

 

[Monkeh]

I've read that Microsoft only had license for 32bit Windows, such as XP, to allow upto 4GB RAM.


Why would such a license even exist?

Whoever you got that from is an idiot.

http://en.wikipedia.org/wiki/32-bit

 

[Astra99]

The 32-bit version of Windows only supports a maximum of 4GB RAM. This is not due to any licencing system, but to the fact that 4GB is the maximum which 32 bits can support. 4GB is 4,294,967,296 bytes. The "capacity" of 32 bits (if each bit is set to 1) has a decimal value of 4,294,967,295 bytes. (Note that a bit can only have two values, zero or one)

To put it another way - You can't get a quart in a pint pot!

 

[DIYspanner]

Thanks for the explanations folks.

So the 32 bit capacity of the OS allows 2^32 = 4'294'967'286 allocations for bytes of data in RAM, hence a maximum of 4GB

Where as a 64 bit system would allow 2^64 allocations of byte in RAM?


Regarding 32 bit RAM capacity, I've seen links to patches that claim to allow greater than 4GB with 32 bit Windows - obviously nonsense it seems!

 

[Monkeh]

Thanks for the explanations folks.

So the 32 bit capacity of the OS allows 2^32 = 4'294'967'286 allocations for bytes of data in RAM, hence a maximum of 4GB

Yes.

Where as a 64 bit system would allow 2^64 allocations of byte in RAM?

Theoretically.

Regarding 32 bit RAM capacity, I've seen links to patches that claim to allow greater than 4GB with 32 bit Windows - obviously nonsense it seems!

You should read my link and the related pages.

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

 

[DIYspanner]

Thanks Monkeh, I shall read and digest with interest.

I actually use 32 bit XP Pro on a P4 machine which only supports 2GB PC3200 or 3GB PC2700 although I'd love a 478 P4 motherboard that supports 4GB PC3200.

 

[Monkeh]

Thanks Monkeh, I shall read and digest with interest.

I actually use 32 bit XP Pro on a P4 machine which only supports 2GB PC3200 or 3GB PC2700 although I'd love a 478 P4 motherboard that supports 4GB PC3200.

You wouldn't really get anything out of it with XP anyway. Something made this decade would be a better buy than a manky old P4 board.

 

[skhudy]

Something made this decade would be a better buy than a manky old P4 board.

lol

 

[Door7000]

Even if you do have 4Gb with a 32bit O/S not all of that will be available. Some Microsoft O/S will only allow the use of around 3.2Gb so 800Mb will be wasted.

Although 4Gb is the max size for 32bit software you can use more than that if you wish.

It is possible to run 8Gb, with 4Gb for the O/S and 4Gb for something like a RAMDISK.

 

[Monkeh]

Even if you do have 4Gb with a 32bit O/S not all of that will be available. Some Microsoft O/S will only allow the use of around 3.2Gb so 800Mb will be wasted.

This is not entirely the fault of the OS, it's a hardware thing.

Although 4Gb is the max size for 32bit software you can use more than that if you wish.

It is possible to run 8Gb, with 4Gb for the O/S and 4Gb for something like a RAMDISK.

Not with a consumer 32-bit version of Windows you can't. A a server edition could do that, but why would you? You can use all that RAM, just not with one program.

Also, look into the difference between b and B. It's quite significant. More so than the decimal prefix I'm letting slide.

 

[Door7000]

Surely it is the O/S

I can run 32bit on this box and the max is 4Gb. I can run 64bit on the same box and get > 4Gb.

You can certainly run a ramdisk on home / consumer windows. Used them for years. Another box next to me is running just that.

32bit Windows 8.
8Gb Ram, 4Gb for O/S (3.2Gb usable), 4Gb running in a Ramdrive.

Ramdrives are great for number crunching / working on large files.

 

[Monkeh]

Surely it is the O/S

I can run 32bit on this box and the max is 4Gb. I can run 64bit on the same box and get > 4Gb.

Being limited to below 4GiB with a 32-bit OS is hardware related.

You can certainly run a ramdisk on home / consumer windows. Used them for years. Another box next to me is running just that.

32bit Windows 8.
8Gb Ram, 4Gb for O/S (3.2Gb usable), 4Gb running in a Ramdrive.

Ramdrives are great for number crunching / working on large files.

Only via nasty BIOS/UEFI tricks supported by a small handful of boards, because the OS can't address the RAM.

Still wondering how you manage to run Windows 8 with 476MiB of RAM.

 

[Door7000]

semantics on the first point.

On the second point. Where did I say I was running Windows 8 with 476Mb of RAM?

I am running it with 8Gb of which 3.2Gb is available for use with the rest hardware reserved

View media item 72342
0-3.2Gb is available for use by Windows 8 32bit
3.2Gb - 4Gb is Hardware Reserved
4Gb - 8Gb is Hardware reserved of which all of this is allocated to a Ramdrive.

 

[Monkeh]

On the second point. Where did I say I was running Windows 8 with 476Mb of RAM?

Every single time you say 4Gb. Although, as you can only use 3.2Gb due to hardware limitations, it's actually 381MiB. Now you're saying you only have 56MiB!

 

[Door7000]

Unusual replies. Think I'll give this section a miss.